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class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2502.14990">arXiv:2502.14990</a> <span> [<a href="https://arxiv.org/pdf/2502.14990">pdf</a>, <a href="https://arxiv.org/format/2502.14990">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Earth and Planetary Astrophysics">astro-ph.EP</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/PSJ/ad62f5">10.3847/PSJ/ad62f5 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The Dynamical State of the Didymos System Before and After the DART Impact </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Richardson%2C+D+C">Derek C. Richardson</a>, <a href="/search/?searchtype=author&query=Agrusa%2C+H+F">Harrison F. Agrusa</a>, <a href="/search/?searchtype=author&query=Barbee%2C+B">Brent Barbee</a>, <a href="/search/?searchtype=author&query=Cueva%2C+R+H">Rachel H. Cueva</a>, <a href="/search/?searchtype=author&query=Ferrari%2C+F">Fabio Ferrari</a>, <a href="/search/?searchtype=author&query=Jacobson%2C+S+A">Seth A. Jacobson</a>, <a href="/search/?searchtype=author&query=Makadia%2C+R">Rahil Makadia</a>, <a href="/search/?searchtype=author&query=Meyer%2C+A+J">Alex J. Meyer</a>, <a href="/search/?searchtype=author&query=Michel%2C+P">Patrick Michel</a>, <a href="/search/?searchtype=author&query=Nakano%2C+R">Ryota Nakano</a>, <a href="/search/?searchtype=author&query=Zhang%2C+Y">Yun Zhang</a>, <a href="/search/?searchtype=author&query=Abell%2C+P">Paul Abell</a>, <a href="/search/?searchtype=author&query=Merrill%2C+C+C">Colby C. Merrill</a>, <a href="/search/?searchtype=author&query=Bagatin%2C+A+C">Adriano Campo Bagatin</a>, <a href="/search/?searchtype=author&query=Barnouin%2C+O">Olivier Barnouin</a>, <a href="/search/?searchtype=author&query=Chabot%2C+N+L">Nancy L. Chabot</a>, <a href="/search/?searchtype=author&query=Cheng%2C+A+F">Andrew F. Cheng</a>, <a href="/search/?searchtype=author&query=Chesley%2C+S+R">Steven R. Chesley</a>, <a href="/search/?searchtype=author&query=Daly%2C+R+T">R. Terik Daly</a>, <a href="/search/?searchtype=author&query=Eggl%2C+S">Siegfried Eggl</a>, <a href="/search/?searchtype=author&query=Ernst%2C+C+M">Carolyn M. Ernst</a>, <a href="/search/?searchtype=author&query=Fahnestock%2C+E+G">Eugene G. Fahnestock</a>, <a href="/search/?searchtype=author&query=Farnham%2C+T+L">Tony L. Farnham</a>, <a href="/search/?searchtype=author&query=Fuentes-Munoz%2C+O">Oscar Fuentes-Munoz</a>, <a href="/search/?searchtype=author&query=Gramigna%2C+E">Edoardo Gramigna</a> , et al. (28 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2502.14990v1-abstract-short" style="display: inline;"> NASA's Double Asteroid Redirection Test (DART) spacecraft impacted Dimorphos, the natural satellite of (65803) Didymos, on 2022 September 26, as a first successful test of kinetic impactor technology for deflecting a potentially hazardous object in space. The experiment resulted in a small change to the dynamical state of the Didymos system consistent with expectations and Level 1 mission requirem… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2502.14990v1-abstract-full').style.display = 'inline'; document.getElementById('2502.14990v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2502.14990v1-abstract-full" style="display: none;"> NASA's Double Asteroid Redirection Test (DART) spacecraft impacted Dimorphos, the natural satellite of (65803) Didymos, on 2022 September 26, as a first successful test of kinetic impactor technology for deflecting a potentially hazardous object in space. The experiment resulted in a small change to the dynamical state of the Didymos system consistent with expectations and Level 1 mission requirements. In the pre-encounter paper Richardson (2022), predictions were put forward regarding the pre- and post-impact dynamical state of the Didymos system. Here we assess these predictions, update preliminary findings published after the impact, report on new findings related to dynamics, and provide implications for ESA's Hera mission to Didymos, scheduled for launch in 2024 with arrival in late December 2026. Pre-encounter predictions tested to date are largely in line with observations, despite the unexpected, flattened appearance of Didymos compared to the radar model and the apparent pre-impact oblate shape of Dimorphos (with implications for the origin of the system that remain under investigation). New findings include that Dimorphos likely became prolate due to the impact and may have entered a tumbling rotation state. A possible detection of a post-impact transient secular decrease in the binary orbital period suggests possible dynamical coupling with persistent ejecta. Timescales for damping of any tumbling and clearing of any debris are uncertain. The largest uncertainty in the momentum transfer enhancement factor of the DART impact remains the mass of Dimorphos, which will be resolved by the Hera mission. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2502.14990v1-abstract-full').style.display = 'none'; document.getElementById('2502.14990v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 20 February, 2025; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2025. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">24 pages, 11 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> The Planetary Science Journal, Volume 5, Issue 8, id.182, 24 pp., 2024 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2406.04864">arXiv:2406.04864</a> <span> [<a href="https://arxiv.org/pdf/2406.04864">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Earth and Planetary Astrophysics">astro-ph.EP</span> </div> </div> <p class="title is-5 mathjax"> Shaking and Tumbling: Short- and Long-Timescale Mechanisms for Resurfacing of Near-Earth Asteroid Surfaces from Planetary Tides and Predictions for the 2029 Earth Encounter by (99942) Apophis </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Ballouz%2C+R+-">R. -L. Ballouz</a>, <a href="/search/?searchtype=author&query=Agrusa%2C+H">H. Agrusa</a>, <a href="/search/?searchtype=author&query=Barnouin%2C+O+S">O. S. Barnouin</a>, <a href="/search/?searchtype=author&query=Walsh%2C+K+J">K. J. Walsh</a>, <a href="/search/?searchtype=author&query=Zhang%2C+Y">Y. Zhang</a>, <a href="/search/?searchtype=author&query=Binzel%2C+R+P">R. P. Binzel</a>, <a href="/search/?searchtype=author&query=Bray%2C+V+J">V. J. Bray</a>, <a href="/search/?searchtype=author&query=DellaGiustina%2C+D+N">D. N. DellaGiustina</a>, <a href="/search/?searchtype=author&query=Jawin%2C+E+R">E. R. Jawin</a>, <a href="/search/?searchtype=author&query=DeMartini%2C+J+V">J. V. DeMartini</a>, <a href="/search/?searchtype=author&query=Marusiak%2C+A">A. Marusiak</a>, <a href="/search/?searchtype=author&query=Michel%2C+P">P. Michel</a>, <a href="/search/?searchtype=author&query=Murdoch%2C+N">N. Murdoch</a>, <a href="/search/?searchtype=author&query=Richardson%2C+D+C">D. C. Richardson</a>, <a href="/search/?searchtype=author&query=Rivera-Valent%C3%ADn%2C+E+G">E. G. Rivera-Valent铆n</a>, <a href="/search/?searchtype=author&query=Rivkin%2C+A+S">A. S. Rivkin</a>, <a href="/search/?searchtype=author&query=Tang%2C+Y">Y. Tang</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2406.04864v2-abstract-short" style="display: inline;"> Spectral characterization of near-Earth asteroids (NEAs) has revealed a continuum of space-weathered states for the surfaces of S-complex NEAs, with Q-class NEAs, an S-complex subclass, most closely matching the un-weathered surfaces of ordinary chondrite meteorites. Dynamical calculations of the orbital evolution of S-complex NEAs revealed that Q-class NEAs tend to have close encounters with terr… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2406.04864v2-abstract-full').style.display = 'inline'; document.getElementById('2406.04864v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2406.04864v2-abstract-full" style="display: none;"> Spectral characterization of near-Earth asteroids (NEAs) has revealed a continuum of space-weathered states for the surfaces of S-complex NEAs, with Q-class NEAs, an S-complex subclass, most closely matching the un-weathered surfaces of ordinary chondrite meteorites. Dynamical calculations of the orbital evolution of S-complex NEAs revealed that Q-class NEAs tend to have close encounters with terrestrial planets, suggesting that planetary tides may play a role in refreshing NEA surfaces. However, the exact physical mechanism(s) that drive resurfacing through tidal encounters and the encounter distance at which these mechanisms are effective, has remained unclear. Through the lens of the upcoming (99942) Apophis encounter with Earth in 2029, we investigate the potential for surface mobilization through tidally-driven seismic shaking over short-timescales during encounter and subsequent surface slope evolution over longer-timescales driven by tumbling. We perform multi-scale numerical modeling and find that the 2029 encounter will induce short-term tidally-driven discrete seismic events that lead to high-frequency (>0.1 Hz) surface accelerations that reach magnitudes similar to Apophis' gravity, and that may be detectable by modern seismometers. It is still unclear if the shaking we model translates to widespread particle mobilization and/or lofting. We also find there will be a significant change in Apophis' tumbling spin state that could lead to longer-term surface refreshing in response to tumbling-induced surface slope changes. We propose that through these mechanisms, space-weathered S-class asteroid surfaces may become refreshed through the exposure of unweathered underlying material. These results will be tested by the future exploration of Apophis by NASA's OSIRIS-APEX. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2406.04864v2-abstract-full').style.display = 'none'; document.getElementById('2406.04864v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 4 October, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 7 June, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">39 pages, 11 figures, Accepted by The Planetary Science Journal</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2406.00379">arXiv:2406.00379</a> <span> [<a href="https://arxiv.org/pdf/2406.00379">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Earth and Planetary Astrophysics">astro-ph.EP</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Geophysics">physics.geo-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.3847/PSJ/ad4266">10.3847/PSJ/ad4266 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Impact disruption of Bjurb枚le porous chondritic projectile </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Kohout%2C+T">Tomas Kohout</a>, <a href="/search/?searchtype=author&query=Pajola%2C+M">Maurizio Pajola</a>, <a href="/search/?searchtype=author&query=Soini%2C+A">Assi-Johanna Soini</a>, <a href="/search/?searchtype=author&query=Lucchetti%2C+A">Alice Lucchetti</a>, <a href="/search/?searchtype=author&query=Luttinen%2C+A">Arto Luttinen</a>, <a href="/search/?searchtype=author&query=Duch%C3%AAne%2C+A">Alexia Duch锚ne</a>, <a href="/search/?searchtype=author&query=Murdoch%2C+N">Naomi Murdoch</a>, <a href="/search/?searchtype=author&query=Luther%2C+R">Robert Luther</a>, <a href="/search/?searchtype=author&query=Chabot%2C+N+L">Nancy L. Chabot</a>, <a href="/search/?searchtype=author&query=Raducan%2C+S+D">Sabina D. Raducan</a>, <a href="/search/?searchtype=author&query=S%C3%A1nchez%2C+P">Paul S谩nchez</a>, <a href="/search/?searchtype=author&query=Barnouin%2C+O+S">Olivier S. Barnouin</a>, <a href="/search/?searchtype=author&query=Rivkin%2C+A+S">Andrew S. Rivkin</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2406.00379v1-abstract-short" style="display: inline;"> The ~200 m/s impact of a single 400-kg Bjurb枚le L/LL ordinary chondrite meteorite onto sea ice resulted in the catastrophic disruption of the projectile. This resulted in a significant fraction of decimeter-sized fragments that exhibit power law cumulative size and mass distributions. This size range is underrepresented in impact experiments and asteroid boulder studies. The Bjurb枚le projectile fr… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2406.00379v1-abstract-full').style.display = 'inline'; document.getElementById('2406.00379v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2406.00379v1-abstract-full" style="display: none;"> The ~200 m/s impact of a single 400-kg Bjurb枚le L/LL ordinary chondrite meteorite onto sea ice resulted in the catastrophic disruption of the projectile. This resulted in a significant fraction of decimeter-sized fragments that exhibit power law cumulative size and mass distributions. This size range is underrepresented in impact experiments and asteroid boulder studies. The Bjurb枚le projectile fragments share similarities in shape (sphericity, and roughness at small and large scale) with asteroid boulders. However, the mean aspect ratio (3D measurement) and apparent aspect ratio (2D measurement) of Bjurb枚le fragment is 0.83 and 0.77, respectively, indicating that Bjurb枚le fragments are more equidimensional compared to both fragments produced in smaller scale impact experiments and asteroid boulders. These differences may be attributed either to the fragment source (projectile vs. target), to the high porosity and low strength of Bjurb枚le, to the lower impact velocity compared with typical asteroid collision velocities, or potentially to fragment erosion during sea sediment penetration or cleaning. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2406.00379v1-abstract-full').style.display = 'none'; document.getElementById('2406.00379v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 1 June, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Data repository https://www.doi.org/10.5281/zenodo.10062980</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> The Planetary Science Journal, 5, 128 (2024) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2405.19764">arXiv:2405.19764</a> <span> [<a href="https://arxiv.org/pdf/2405.19764">pdf</a>, <a href="https://arxiv.org/format/2405.19764">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Earth and Planetary Astrophysics">astro-ph.EP</span> </div> </div> <p class="title is-5 mathjax"> Macro-scale roughness reveals the complex history of asteroids Didymos and Dimorphos </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Vincent%2C+J">Jean-Baptiste Vincent</a>, <a href="/search/?searchtype=author&query=Asphaug%2C+E">Erik Asphaug</a>, <a href="/search/?searchtype=author&query=Barnouin%2C+O">Olivier Barnouin</a>, <a href="/search/?searchtype=author&query=Beccarelli%2C+J">Joel Beccarelli</a>, <a href="/search/?searchtype=author&query=Benavidez%2C+P+G">Paula G. Benavidez</a>, <a href="/search/?searchtype=author&query=Campo-Bagatin%2C+A">Adriano Campo-Bagatin</a>, <a href="/search/?searchtype=author&query=Chabot%2C+N+L">Nancy L. Chabot</a>, <a href="/search/?searchtype=author&query=Ernst%2C+C+M">Carolyn M. Ernst</a>, <a href="/search/?searchtype=author&query=Hasselmann%2C+P+H">Pedro H. Hasselmann</a>, <a href="/search/?searchtype=author&query=Hirabayashi%2C+M">Masatoshi Hirabayashi</a>, <a href="/search/?searchtype=author&query=Ieva%2C+S">Simone Ieva</a>, <a href="/search/?searchtype=author&query=Karatekin%2C+O">Ozgur Karatekin</a>, <a href="/search/?searchtype=author&query=Kasparek%2C+T">Tomas Kasparek</a>, <a href="/search/?searchtype=author&query=Kohout%2C+T">Tomas Kohout</a>, <a href="/search/?searchtype=author&query=Lin%2C+Z">Zhong-Yi Lin</a>, <a href="/search/?searchtype=author&query=Lucchetti%2C+A">Alice Lucchetti</a>, <a href="/search/?searchtype=author&query=Michel%2C+P">Patrick Michel</a>, <a href="/search/?searchtype=author&query=Murdoch%2C+N">Naomi Murdoch</a>, <a href="/search/?searchtype=author&query=Pajola%2C+M">Maurizio Pajola</a>, <a href="/search/?searchtype=author&query=Parro%2C+L+M">Laura M. Parro</a>, <a href="/search/?searchtype=author&query=Raducan%2C+S+D">Sabina D. Raducan</a>, <a href="/search/?searchtype=author&query=Sunshine%2C+J">Jessica Sunshine</a>, <a href="/search/?searchtype=author&query=Tancredi%2C+G">Gonzalo Tancredi</a>, <a href="/search/?searchtype=author&query=Trigo-Rodriguez%2C+J+M">Josep M. Trigo-Rodriguez</a>, <a href="/search/?searchtype=author&query=Zinzi%2C+A">Angelo Zinzi</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2405.19764v1-abstract-short" style="display: inline;"> Morphological mapping is a fundamental step in studying the processes that shaped an asteroid surface. Yet, it is challenging and often requires multiple independent assessments by trained experts. Here, we present fast methods to detect and characterize meaningful terrains from the topographic roughness: entropy of information, and local mean surface orientation. We apply our techniques to Didymo… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.19764v1-abstract-full').style.display = 'inline'; document.getElementById('2405.19764v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2405.19764v1-abstract-full" style="display: none;"> Morphological mapping is a fundamental step in studying the processes that shaped an asteroid surface. Yet, it is challenging and often requires multiple independent assessments by trained experts. Here, we present fast methods to detect and characterize meaningful terrains from the topographic roughness: entropy of information, and local mean surface orientation. We apply our techniques to Didymos and Dimorphos, the target asteroids of NASA's DART mission: first attempt to deflect an asteroid. Our methods reliably identify morphological units at multiple scales. The comparative study reveals various terrain types, signatures of processes that transformed Didymos and Dimorphos. Didymos shows the most heterogeneity and morphology that indicate recent resurfacing events. Dimorphos is comparatively rougher than Didymos, which may result from the formation process of the binary pair and past interaction between the two bodies. Our methods can be readily applied to other bodies and data sets. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.19764v1-abstract-full').style.display = 'none'; document.getElementById('2405.19764v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 30 May, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">submitted to PSJ</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2403.00667">arXiv:2403.00667</a> <span> [<a href="https://arxiv.org/pdf/2403.00667">pdf</a>, <a href="https://arxiv.org/format/2403.00667">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Earth and Planetary Astrophysics">astro-ph.EP</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1038/s41550-024-02200-3">10.1038/s41550-024-02200-3 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Physical properties of asteroid Dimorphos as derived from the DART impact </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Raducan%2C+S+D">S. D. Raducan</a>, <a href="/search/?searchtype=author&query=Jutzi%2C+M">M. Jutzi</a>, <a href="/search/?searchtype=author&query=Cheng%2C+A+F">A. F. Cheng</a>, <a href="/search/?searchtype=author&query=Zhang%2C+Y">Y. Zhang</a>, <a href="/search/?searchtype=author&query=Barnouin%2C+O">O. Barnouin</a>, <a href="/search/?searchtype=author&query=Collins%2C+G+S">G. S. Collins</a>, <a href="/search/?searchtype=author&query=Daly%2C+R+T">R. T. Daly</a>, <a href="/search/?searchtype=author&query=Davison%2C+T+M">T. M. Davison</a>, <a href="/search/?searchtype=author&query=Ernst%2C+C+M">C. M. Ernst</a>, <a href="/search/?searchtype=author&query=Farnham%2C+T+L">T. L. Farnham</a>, <a href="/search/?searchtype=author&query=Ferrari%2C+F">F. Ferrari</a>, <a href="/search/?searchtype=author&query=Hirabayashi%2C+M">M. Hirabayashi</a>, <a href="/search/?searchtype=author&query=Kumamoto%2C+K+M">K. M. Kumamoto</a>, <a href="/search/?searchtype=author&query=Michel%2C+P">P. Michel</a>, <a href="/search/?searchtype=author&query=Murdoch%2C+N">N. Murdoch</a>, <a href="/search/?searchtype=author&query=Nakano%2C+R">R. Nakano</a>, <a href="/search/?searchtype=author&query=Pajola%2C+M">M. Pajola</a>, <a href="/search/?searchtype=author&query=Rossi%2C+A">A. Rossi</a>, <a href="/search/?searchtype=author&query=Agrusa%2C+H+F">H. F. Agrusa</a>, <a href="/search/?searchtype=author&query=Barbee%2C+B+W">B. W. Barbee</a>, <a href="/search/?searchtype=author&query=Syal%2C+M+B">M. Bruck Syal</a>, <a href="/search/?searchtype=author&query=Chabot%2C+N+L">N. L. Chabot</a>, <a href="/search/?searchtype=author&query=Dotto%2C+E">E. Dotto</a>, <a href="/search/?searchtype=author&query=Fahnestock%2C+E+G">E. G. Fahnestock</a>, <a href="/search/?searchtype=author&query=Hasselmann%2C+P+H">P. H. Hasselmann</a> , et al. (17 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2403.00667v1-abstract-short" style="display: inline;"> On September 26, 2022, NASA's Double Asteroid Redirection Test (DART) mission successfully impacted Dimorphos, the natural satellite of the binary near-Earth asteroid (65803) Didymos. Numerical simulations of the impact provide a means to explore target surface material properties and structures, consistent with the observed momentum deflection efficiency, ejecta cone geometry, and ejected mass. O… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2403.00667v1-abstract-full').style.display = 'inline'; document.getElementById('2403.00667v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2403.00667v1-abstract-full" style="display: none;"> On September 26, 2022, NASA's Double Asteroid Redirection Test (DART) mission successfully impacted Dimorphos, the natural satellite of the binary near-Earth asteroid (65803) Didymos. Numerical simulations of the impact provide a means to explore target surface material properties and structures, consistent with the observed momentum deflection efficiency, ejecta cone geometry, and ejected mass. Our simulation, which best matches observations, indicates that Dimorphos is weak, with a cohesive strength of less than a few pascals (Pa), similar to asteroids (162173) Ryugu and (101955) Bennu. We find that a bulk density of Dimorphos, rhoB, lower than 2400 kg/m3, and a low volume fraction of boulders (<40 vol%) on the surface and in the shallow subsurface, are consistent with measured data from the DART experiment. These findings suggest Dimorphos is a rubble pile that might have formed through rotational mass shedding and re-accumulation from Didymos. Our simulations indicate that the DART impact caused global deformation and resurfacing of Dimorphos. ESA's upcoming Hera mission may find a re-shaped asteroid, rather than a well-defined crater. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2403.00667v1-abstract-full').style.display = 'none'; document.getElementById('2403.00667v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 1 March, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2303.03464">arXiv:2303.03464</a> <span> [<a href="https://arxiv.org/pdf/2303.03464">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Earth and Planetary Astrophysics">astro-ph.EP</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1038/s41586-023-05878-z">10.1038/s41586-023-05878-z <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Momentum Transfer from the DART Mission Kinetic Impact on Asteroid Dimorphos </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Cheng%2C+A+F">Andrew F. Cheng</a>, <a href="/search/?searchtype=author&query=Agrusa%2C+H+F">Harrison F. Agrusa</a>, <a href="/search/?searchtype=author&query=Barbee%2C+B+W">Brent W. Barbee</a>, <a href="/search/?searchtype=author&query=Meyer%2C+A+J">Alex J. Meyer</a>, <a href="/search/?searchtype=author&query=Farnham%2C+T+L">Tony L. Farnham</a>, <a href="/search/?searchtype=author&query=Raducan%2C+S+D">Sabina D. Raducan</a>, <a href="/search/?searchtype=author&query=Richardson%2C+D+C">Derek C. Richardson</a>, <a href="/search/?searchtype=author&query=Dotto%2C+E">Elisabetta Dotto</a>, <a href="/search/?searchtype=author&query=Zinzi%2C+A">Angelo Zinzi</a>, <a href="/search/?searchtype=author&query=Della+Corte%2C+V">Vincenzo Della Corte</a>, <a href="/search/?searchtype=author&query=Statler%2C+T+S">Thomas S. Statler</a>, <a href="/search/?searchtype=author&query=Chesley%2C+S">Steven Chesley</a>, <a href="/search/?searchtype=author&query=Naidu%2C+S+P">Shantanu P. Naidu</a>, <a href="/search/?searchtype=author&query=Hirabayashi%2C+M">Masatoshi Hirabayashi</a>, <a href="/search/?searchtype=author&query=Li%2C+J">Jian-Yang Li</a>, <a href="/search/?searchtype=author&query=Eggl%2C+S">Siegfried Eggl</a>, <a href="/search/?searchtype=author&query=Barnouin%2C+O+S">Olivier S. Barnouin</a>, <a href="/search/?searchtype=author&query=Chabot%2C+N+L">Nancy L. Chabot</a>, <a href="/search/?searchtype=author&query=Chocron%2C+S">Sidney Chocron</a>, <a href="/search/?searchtype=author&query=Collins%2C+G+S">Gareth S. Collins</a>, <a href="/search/?searchtype=author&query=Daly%2C+R+T">R. Terik Daly</a>, <a href="/search/?searchtype=author&query=Davison%2C+T+M">Thomas M. Davison</a>, <a href="/search/?searchtype=author&query=DeCoster%2C+M+E">Mallory E. DeCoster</a>, <a href="/search/?searchtype=author&query=Ernst%2C+C+M">Carolyn M. Ernst</a>, <a href="/search/?searchtype=author&query=Ferrari%2C+F">Fabio Ferrari</a> , et al. (44 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2303.03464v1-abstract-short" style="display: inline;"> The NASA Double Asteroid Redirection Test (DART) mission performed a kinetic impact on asteroid Dimorphos, the satellite of the binary asteroid (65803) Didymos, at 23:14 UTC on September 26, 2022 as a planetary defense test. DART was the first hypervelocity impact experiment on an asteroid at size and velocity scales relevant to planetary defense, intended to validate kinetic impact as a means of… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.03464v1-abstract-full').style.display = 'inline'; document.getElementById('2303.03464v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2303.03464v1-abstract-full" style="display: none;"> The NASA Double Asteroid Redirection Test (DART) mission performed a kinetic impact on asteroid Dimorphos, the satellite of the binary asteroid (65803) Didymos, at 23:14 UTC on September 26, 2022 as a planetary defense test. DART was the first hypervelocity impact experiment on an asteroid at size and velocity scales relevant to planetary defense, intended to validate kinetic impact as a means of asteroid deflection. Here we report the first determination of the momentum transferred to an asteroid by kinetic impact. Based on the change in the binary orbit period, we find an instantaneous reduction in Dimorphos's along-track orbital velocity component of 2.70 +/- 0.10 mm/s, indicating enhanced momentum transfer due to recoil from ejecta streams produced by the impact. For a Dimorphos bulk density range of 1,500 to 3,300 kg/m$^3$, we find that the expected value of the momentum enhancement factor, $尾$, ranges between 2.2 and 4.9, depending on the mass of Dimorphos. If Dimorphos and Didymos are assumed to have equal densities of 2,400 kg/m$^3$, $尾$= 3.61 +0.19/-0.25 (1 $蟽$). These $尾$ values indicate that significantly more momentum was transferred to Dimorphos from the escaping impact ejecta than was incident with DART. Therefore, the DART kinetic impact was highly effective in deflecting the asteroid Dimorphos. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.03464v1-abstract-full').style.display = 'none'; document.getElementById('2303.03464v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 6 March, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">accepted by Nature</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2303.02248">arXiv:2303.02248</a> <span> [<a href="https://arxiv.org/pdf/2303.02248">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Earth and Planetary Astrophysics">astro-ph.EP</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1038/s41586-023-05810-5">10.1038/s41586-023-05810-5 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Successful Kinetic Impact into an Asteroid for Planetary Defense </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Daly%2C+R+T">R. Terik Daly</a>, <a href="/search/?searchtype=author&query=Ernst%2C+C+M">Carolyn M. Ernst</a>, <a href="/search/?searchtype=author&query=Barnouin%2C+O+S">Olivier S. Barnouin</a>, <a href="/search/?searchtype=author&query=Chabot%2C+N+L">Nancy L. Chabot</a>, <a href="/search/?searchtype=author&query=Rivkin%2C+A+S">Andrew S. Rivkin</a>, <a href="/search/?searchtype=author&query=Cheng%2C+A+F">Andrew F. Cheng</a>, <a href="/search/?searchtype=author&query=Adams%2C+E+Y">Elena Y. Adams</a>, <a href="/search/?searchtype=author&query=Agrusa%2C+H+F">Harrison F. Agrusa</a>, <a href="/search/?searchtype=author&query=Abel%2C+E+D">Elisabeth D. Abel</a>, <a href="/search/?searchtype=author&query=Alford%2C+A+L">Amy L. Alford</a>, <a href="/search/?searchtype=author&query=Asphaug%2C+E+I">Erik I. Asphaug</a>, <a href="/search/?searchtype=author&query=Atchison%2C+J+A">Justin A. Atchison</a>, <a href="/search/?searchtype=author&query=Badger%2C+A+R">Andrew R. Badger</a>, <a href="/search/?searchtype=author&query=Baki%2C+P">Paul Baki</a>, <a href="/search/?searchtype=author&query=Ballouz%2C+R">Ronald-L. Ballouz</a>, <a href="/search/?searchtype=author&query=Bekker%2C+D+L">Dmitriy L. Bekker</a>, <a href="/search/?searchtype=author&query=Bellerose%2C+J">Julie Bellerose</a>, <a href="/search/?searchtype=author&query=Bhaskaran%2C+S">Shyam Bhaskaran</a>, <a href="/search/?searchtype=author&query=Buratti%2C+B+J">Bonnie J. Buratti</a>, <a href="/search/?searchtype=author&query=Cambioni%2C+S">Saverio Cambioni</a>, <a href="/search/?searchtype=author&query=Chen%2C+M+H">Michelle H. Chen</a>, <a href="/search/?searchtype=author&query=Chesley%2C+S+R">Steven R. Chesley</a>, <a href="/search/?searchtype=author&query=Chiu%2C+G">George Chiu</a>, <a href="/search/?searchtype=author&query=Collins%2C+G+S">Gareth S. Collins</a>, <a href="/search/?searchtype=author&query=Cox%2C+M+W">Matthew W. Cox</a> , et al. (76 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2303.02248v1-abstract-short" style="display: inline;"> While no known asteroid poses a threat to Earth for at least the next century, the catalog of near-Earth asteroids is incomplete for objects whose impacts would produce regional devastation. Several approaches have been proposed to potentially prevent an asteroid impact with Earth by deflecting or disrupting an asteroid. A test of kinetic impact technology was identified as the highest priority sp… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.02248v1-abstract-full').style.display = 'inline'; document.getElementById('2303.02248v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2303.02248v1-abstract-full" style="display: none;"> While no known asteroid poses a threat to Earth for at least the next century, the catalog of near-Earth asteroids is incomplete for objects whose impacts would produce regional devastation. Several approaches have been proposed to potentially prevent an asteroid impact with Earth by deflecting or disrupting an asteroid. A test of kinetic impact technology was identified as the highest priority space mission related to asteroid mitigation. NASA's Double Asteroid Redirection Test (DART) mission is the first full-scale test of kinetic impact technology. The mission's target asteroid was Dimorphos, the secondary member of the S-type binary near-Earth asteroid (65803) Didymos. This binary asteroid system was chosen to enable ground-based telescopes to quantify the asteroid deflection caused by DART's impact. While past missions have utilized impactors to investigate the properties of small bodies those earlier missions were not intended to deflect their targets and did not achieve measurable deflections. Here we report the DART spacecraft's autonomous kinetic impact into Dimorphos and reconstruct the impact event, including the timeline leading to impact, the location and nature of the DART impact site, and the size and shape of Dimorphos. The successful impact of the DART spacecraft with Dimorphos and the resulting change in Dimorphos's orbit demonstrates that kinetic impactor technology is a viable technique to potentially defend Earth if necessary. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.02248v1-abstract-full').style.display = 'none'; document.getElementById('2303.02248v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 3 March, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted by Nature</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2209.11873">arXiv:2209.11873</a> <span> [<a href="https://arxiv.org/pdf/2209.11873">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Earth and Planetary Astrophysics">astro-ph.EP</span> </div> </div> <p class="title is-5 mathjax"> After DART: Using the first full-scale test of a kinetic impactor to inform a future planetary defense mission </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Statler%2C+T+S">Thomas S. Statler</a>, <a href="/search/?searchtype=author&query=Raducan%2C+S+D">Sabina D. Raducan</a>, <a href="/search/?searchtype=author&query=Barnouin%2C+O+S">Olivier S. Barnouin</a>, <a href="/search/?searchtype=author&query=DeCoster%2C+M+E">Mallory E. DeCoster</a>, <a href="/search/?searchtype=author&query=Chesley%2C+S+R">Steven R. Chesley</a>, <a href="/search/?searchtype=author&query=Barbee%2C+B">Brent Barbee</a>, <a href="/search/?searchtype=author&query=Agrusa%2C+H+F">Harrison F. Agrusa</a>, <a href="/search/?searchtype=author&query=Cambioni%2C+S">Saverio Cambioni</a>, <a href="/search/?searchtype=author&query=Cheng%2C+A+F">Andrew F. Cheng</a>, <a href="/search/?searchtype=author&query=Dotto%2C+E">Elisabetta Dotto</a>, <a href="/search/?searchtype=author&query=Eggl%2C+S">Siegfried Eggl</a>, <a href="/search/?searchtype=author&query=Fahnestock%2C+E+G">Eugene G. Fahnestock</a>, <a href="/search/?searchtype=author&query=Ferrari%2C+F">Fabio Ferrari</a>, <a href="/search/?searchtype=author&query=Graninger%2C+D">Dawn Graninger</a>, <a href="/search/?searchtype=author&query=Herique%2C+A">Alain Herique</a>, <a href="/search/?searchtype=author&query=Herreros%2C+I">Isabel Herreros</a>, <a href="/search/?searchtype=author&query=Hirabayashi%2C+M">Masatoshi Hirabayashi</a>, <a href="/search/?searchtype=author&query=Ivanovski%2C+S">Stavro Ivanovski</a>, <a href="/search/?searchtype=author&query=Jutzi%2C+M">Martin Jutzi</a>, <a href="/search/?searchtype=author&query=Karatekin%2C+%C3%96">脰zg眉r Karatekin</a>, <a href="/search/?searchtype=author&query=Lucchetti%2C+A">Alice Lucchetti</a>, <a href="/search/?searchtype=author&query=Luther%2C+R">Robert Luther</a>, <a href="/search/?searchtype=author&query=Makadia%2C+R">Rahil Makadia</a>, <a href="/search/?searchtype=author&query=Marzari%2C+F">Francesco Marzari</a>, <a href="/search/?searchtype=author&query=Michel%2C+P">Patrick Michel</a> , et al. (16 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2209.11873v1-abstract-short" style="display: inline;"> NASA's Double Asteroid Redirection Test (DART) is the first full-scale test of an asteroid deflection technology. Results from the hypervelocity kinetic impact and Earth-based observations, coupled with LICIACube and the later Hera mission, will result in measurement of the momentum transfer efficiency accurate to ~10% and characterization of the Didymos binary system. But DART is a single experim… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2209.11873v1-abstract-full').style.display = 'inline'; document.getElementById('2209.11873v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2209.11873v1-abstract-full" style="display: none;"> NASA's Double Asteroid Redirection Test (DART) is the first full-scale test of an asteroid deflection technology. Results from the hypervelocity kinetic impact and Earth-based observations, coupled with LICIACube and the later Hera mission, will result in measurement of the momentum transfer efficiency accurate to ~10% and characterization of the Didymos binary system. But DART is a single experiment; how could these results be used in a future planetary defense necessity involving a different asteroid? We examine what aspects of Dimorphos's response to kinetic impact will be constrained by DART results; how these constraints will help refine knowledge of the physical properties of asteroidal materials and predictive power of impact simulations; what information about a potential Earth impactor could be acquired before a deflection effort; and how design of a deflection mission should be informed by this understanding. We generalize the momentum enhancement factor $尾$, showing that a particular direction-specific $尾$ will be directly determined by the DART results, and that a related direction-specific $尾$ is a figure of merit for a kinetic impact mission. The DART $尾$ determination constrains the ejecta momentum vector, which, with hydrodynamic simulations, constrains the physical properties of Dimorphos's near-surface. In a hypothetical planetary defense exigency, extrapolating these constraints to a newly discovered asteroid will require Earth-based observations and benefit from in-situ reconnaissance. We show representative predictions for momentum transfer based on different levels of reconnaissance and discuss strategic targeting to optimize the deflection and reduce the risk of a counterproductive deflection in the wrong direction. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2209.11873v1-abstract-full').style.display = 'none'; document.getElementById('2209.11873v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 23 September, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">30 pages, 7 figures. Planetary Science Journal, in press, accepted 2022 September 22</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2208.01940">arXiv:2208.01940</a> <span> [<a href="https://arxiv.org/pdf/2208.01940">pdf</a>, <a href="https://arxiv.org/format/2208.01940">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Earth and Planetary Astrophysics">astro-ph.EP</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1007/s11214-022-00945-9">10.1007/s11214-022-00945-9 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The Mars Microphone onboard SuperCam </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Mimoun%2C+D">D. Mimoun</a>, <a href="/search/?searchtype=author&query=Cadu%2C+A">A. Cadu</a>, <a href="/search/?searchtype=author&query=Murdoch%2C+N">N. Murdoch</a>, <a href="/search/?searchtype=author&query=Sournac%2C+A">A. Sournac</a>, <a href="/search/?searchtype=author&query=Parot%2C+Y">Y. Parot</a>, <a href="/search/?searchtype=author&query=Bernardi%2C+P">P. Bernardi</a>, <a href="/search/?searchtype=author&query=Chide%2C+B">B. Chide</a>, <a href="/search/?searchtype=author&query=Pilleri%2C+P">P. Pilleri</a>, <a href="/search/?searchtype=author&query=Stott%2C+A">A. Stott</a>, <a href="/search/?searchtype=author&query=Gillier%2C+M">M. Gillier</a>, <a href="/search/?searchtype=author&query=Sridhar%2C+V">V. Sridhar</a>, <a href="/search/?searchtype=author&query=Maurice%2C+S">S. Maurice</a>, <a href="/search/?searchtype=author&query=Wiens%2C+R+C">R. C. Wiens</a>, <a href="/search/?searchtype=author&query=team%2C+t+S">the SuperCam team</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2208.01940v1-abstract-short" style="display: inline;"> The Mars Microphone is one of the five measurement techniques of SuperCam, an improved version of the ChemCam instrument that has been functioning aboard the Curiosity rover for several years. SuperCam is located on the Rover's Mast Unit, to take advantage of the unique pointing capabilities of the rover's head. In addition to being the first instrument to record sounds on Mars, the SuperCam Micro… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2208.01940v1-abstract-full').style.display = 'inline'; document.getElementById('2208.01940v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2208.01940v1-abstract-full" style="display: none;"> The Mars Microphone is one of the five measurement techniques of SuperCam, an improved version of the ChemCam instrument that has been functioning aboard the Curiosity rover for several years. SuperCam is located on the Rover's Mast Unit, to take advantage of the unique pointing capabilities of the rover's head. In addition to being the first instrument to record sounds on Mars, the SuperCam Microphone can address several original scientific objectives: the study of sound associated with laser impacts on Martian rocks to better understand their mechanical properties, the improvement of our knowledge of atmospheric phenomena at the surface of Mars: atmospheric turbulence, convective vortices, dust lifting processes and wind interactions with the rover itself. The microphone will also help our understanding of the sound signature of the different movements of the rover: operations of the robotic arm and the mast, driving on the rough floor of Mars, monitoring of the pumps, etc ... The SuperCam Microphone was delivered to the SuperCam team in early 2019 and integrated at the Jet Propulsion Laboratory (JPL, Pasadena, CA) with the complete SuperCam instrument. The Mars 2020 Mission launched in July 2020 and landed on Mars on February 18th 2021. The mission operations are expected to last until at least August 2023. The microphone is operating perfectly. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2208.01940v1-abstract-full').style.display = 'none'; document.getElementById('2208.01940v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 3 August, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">40 pages</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2110.06113">arXiv:2110.06113</a> <span> [<a href="https://arxiv.org/pdf/2110.06113">pdf</a>, <a href="https://arxiv.org/format/2110.06113">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Earth and Planetary Astrophysics">astro-ph.EP</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Atmospheric and Oceanic Physics">physics.ao-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1029/2021GL095453">10.1029/2021GL095453 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Seasonal Variability of the Daytime and Nighttime Atmospheric Turbulence Experienced by InSight on Mars </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Chatain%2C+A">Audrey Chatain</a>, <a href="/search/?searchtype=author&query=Spiga%2C+A">Aymeric Spiga</a>, <a href="/search/?searchtype=author&query=Banfield%2C+D">Don Banfield</a>, <a href="/search/?searchtype=author&query=Forget%2C+F">Francois Forget</a>, <a href="/search/?searchtype=author&query=Murdoch%2C+N">Naomi Murdoch</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2110.06113v2-abstract-short" style="display: inline;"> The InSight mission, featuring continuous high-frequency high-sensitivity pressure measurements, is in ideal position to study the active atmospheric turbulence of Mars. Data acquired during 1.25 Martian year allows us to study the seasonal evolution of turbulence and its diurnal cycle. We investigate vortices (abrupt pressure drops), local turbulence (frequency range 0.01-2 Hz) and non-local turb… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2110.06113v2-abstract-full').style.display = 'inline'; document.getElementById('2110.06113v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2110.06113v2-abstract-full" style="display: none;"> The InSight mission, featuring continuous high-frequency high-sensitivity pressure measurements, is in ideal position to study the active atmospheric turbulence of Mars. Data acquired during 1.25 Martian year allows us to study the seasonal evolution of turbulence and its diurnal cycle. We investigate vortices (abrupt pressure drops), local turbulence (frequency range 0.01-2 Hz) and non-local turbulence often caused by convection cells and plumes (frequency range 0.002-0.01 Hz). Contrary to non-local turbulence, local turbulence is strongly sensitive at all local times and seasons to the ambient wind. We report many remarkable events with the arrival of northern autumn at the InSight landing site: a spectacular burst of daytime vortices, the appearance of nighttime vortices, and the development of nighttime local turbulence as intense as its daytime counterpart. Nighttime turbulence at this dusty season appears as a result of the combination of a stronger low-level jet, producing shear-driven turbulence, and a weaker stability. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2110.06113v2-abstract-full').style.display = 'none'; document.getElementById('2110.06113v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 29 October, 2021; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 12 October, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">15 pages, 5 figures, accepted version of the manuscript published in GRL</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Geophysical Research Letters, 48, e2021GL095453 (2021) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2009.10448">arXiv:2009.10448</a> <span> [<a href="https://arxiv.org/pdf/2009.10448">pdf</a>, <a href="https://arxiv.org/format/2009.10448">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Earth and Planetary Astrophysics">astro-ph.EP</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Soft Condensed Matter">cond-mat.soft</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnras/staa2454">10.1093/mnras/staa2454 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Validating N-body code Chrono for granular DEM simulations in reduced-gravity environments </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Sunday%2C+C">Cecily Sunday</a>, <a href="/search/?searchtype=author&query=Murdoch%2C+N">Naomi Murdoch</a>, <a href="/search/?searchtype=author&query=Tardivel%2C+S">Simon Tardivel</a>, <a href="/search/?searchtype=author&query=Schwartz%2C+S+R">Stephen R. Schwartz</a>, <a href="/search/?searchtype=author&query=Michel%2C+P">Patrick Michel</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2009.10448v1-abstract-short" style="display: inline;"> The Discrete Element Method (DEM) is frequently used to model complex granular systems and to augment the knowledge that we obtain through theory, experimentation, and real-world observations. Numerical simulations are a particularly powerful tool for studying the regolith-covered surfaces of asteroids, comets, and small moons, where reduced-gravity environments produce ill-defined flow behaviors.… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2009.10448v1-abstract-full').style.display = 'inline'; document.getElementById('2009.10448v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2009.10448v1-abstract-full" style="display: none;"> The Discrete Element Method (DEM) is frequently used to model complex granular systems and to augment the knowledge that we obtain through theory, experimentation, and real-world observations. Numerical simulations are a particularly powerful tool for studying the regolith-covered surfaces of asteroids, comets, and small moons, where reduced-gravity environments produce ill-defined flow behaviors. In this work, we present a method for validating soft-sphere DEM codes for both terrestrial and small-body granular environments. The open-source code Chrono is modified and evaluated first with a series of simple two-body-collision tests, and then, with a set of piling and tumbler tests. In the piling tests, we vary the coefficient of rolling friction to calibrate the simulations against experiments with 1 mm glass beads. Then, we use the friction coefficient to model the flow of 1 mm glass beads in a rotating drum, using a drum configuration from a previous experimental study. We measure the dynamic angle of repose, the flowing layer thickness, and the flowing layer velocity for tests with different particle sizes, contact force models, coefficients of rolling friction, cohesion levels, drum rotation speeds and gravity levels. The tests show that the same flow patterns can be observed at Earth and reduced-gravity levels if the drum rotation speed and the gravity-level are set according to the dimensionless parameter known as the Froude number. Chrono is successfully validated against known flow behaviors at different gravity and cohesion levels, and will be used to study small-body regolith dynamics in future works. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2009.10448v1-abstract-full').style.display = 'none'; document.getElementById('2009.10448v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 22 September, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Monthly Notices of the Royal Astronomical Society 498.1 (2020): 1062-1079 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2005.01134">arXiv:2005.01134</a> <span> [<a href="https://arxiv.org/pdf/2005.01134">pdf</a>, <a href="https://arxiv.org/format/2005.01134">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Earth and Planetary Astrophysics">astro-ph.EP</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Atmospheric and Oceanic Physics">physics.ao-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Fluid Dynamics">physics.flu-dyn</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1029/2020JE006511">10.1029/2020JE006511 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A study of daytime convective vortices and turbulence in the martian Planetary Boundary Layer based on half-a-year of InSight atmospheric measurements and Large-Eddy Simulations </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Spiga%2C+A">Aymeric Spiga</a>, <a href="/search/?searchtype=author&query=Murdoch%2C+N">Naomi Murdoch</a>, <a href="/search/?searchtype=author&query=Lorenz%2C+R">Ralph Lorenz</a>, <a href="/search/?searchtype=author&query=Forget%2C+F">Fran莽ois Forget</a>, <a href="/search/?searchtype=author&query=Newman%2C+C">Claire Newman</a>, <a href="/search/?searchtype=author&query=Rodriguez%2C+S">S茅bastien Rodriguez</a>, <a href="/search/?searchtype=author&query=Pla-Garcia%2C+J">Jorge Pla-Garcia</a>, <a href="/search/?searchtype=author&query=Vi%C3%BAdez-Moreiras%2C+D">Daniel Vi煤dez-Moreiras</a>, <a href="/search/?searchtype=author&query=Banfield%2C+D">Don Banfield</a>, <a href="/search/?searchtype=author&query=Perrin%2C+C">Cl茅ment Perrin</a>, <a href="/search/?searchtype=author&query=Mueller%2C+N+T">Nils T. Mueller</a>, <a href="/search/?searchtype=author&query=Lemmon%2C+M">Mark Lemmon</a>, <a href="/search/?searchtype=author&query=Millour%2C+E">Ehouarn Millour</a>, <a href="/search/?searchtype=author&query=Banerdt%2C+W+B">W. Bruce Banerdt</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2005.01134v3-abstract-short" style="display: inline;"> Studying the atmospheric Planetary Boundary Layer (PBL) is crucial to understand the climate of a planet. The meteorological measurements by the instruments onboard InSight at a latitude of 4.5$^{\circ}$N make a uniquely rich dataset to study the active turbulent dynamics of the daytime PBL on Mars. Here we use the high-sensitivity continuous pressure, wind, temperature measurements in the first 4… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2005.01134v3-abstract-full').style.display = 'inline'; document.getElementById('2005.01134v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2005.01134v3-abstract-full" style="display: none;"> Studying the atmospheric Planetary Boundary Layer (PBL) is crucial to understand the climate of a planet. The meteorological measurements by the instruments onboard InSight at a latitude of 4.5$^{\circ}$N make a uniquely rich dataset to study the active turbulent dynamics of the daytime PBL on Mars. Here we use the high-sensitivity continuous pressure, wind, temperature measurements in the first 400 sols of InSight operations (from northern late winter to midsummer) to analyze wind gusts, convective cells and vortices in Mars' daytime PBL. We compare InSight measurements to turbulence-resolving Large-Eddy Simulations (LES). The daytime PBL turbulence at the InSight landing site is very active, with clearly identified signatures of convective cells and a vast population of 6000 recorded vortex encounters, adequately represented by a power-law with a 3.4 exponent. While the daily variability of vortex encounters at InSight can be explained by the statistical nature of turbulence, the seasonal variability is positively correlated with ambient wind speed, which is supported by LES. However, wind gustiness is positively correlated to surface temperature rather than ambient wind speed and sensible heat flux, confirming the radiative control of the daytime martian PBL; and fewer convective vortices are forming in LES when the background wind is doubled. Thus, the long-term seasonal variability of vortex encounters at the InSight landing site is mainly controlled by the advection of convective vortices by ambient wind speed. Typical tracks followed by vortices forming in the LES show a similar distribution in direction and length as orbital imagery. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2005.01134v3-abstract-full').style.display = 'none'; document.getElementById('2005.01134v3-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 4 November, 2020; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 3 May, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">44 pages, 19 figures, revised manuscript after peer-reviewed comments for consideration in Journal of Geophysical Research Planets (InSight special issue)</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2003.08959">arXiv:2003.08959</a> <span> [<a href="https://arxiv.org/pdf/2003.08959">pdf</a>, <a href="https://arxiv.org/format/2003.08959">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Geophysics">physics.geo-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Earth and Planetary Astrophysics">astro-ph.EP</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1029/2019JE006353">10.1029/2019JE006353 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> On-deck seismology: Lessons from InSight for future planetary seismology </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Panning%2C+M+P">Mark P. Panning</a>, <a href="/search/?searchtype=author&query=Pike%2C+W+T">W. Tom Pike</a>, <a href="/search/?searchtype=author&query=Lognonn%C3%A9%2C+P">Philippe Lognonn茅</a>, <a href="/search/?searchtype=author&query=Banerdt%2C+W+B">W. Bruce Banerdt</a>, <a href="/search/?searchtype=author&query=Murdoch%2C+N">Naomi Murdoch</a>, <a href="/search/?searchtype=author&query=Banfield%2C+D">Don Banfield</a>, <a href="/search/?searchtype=author&query=Charalambous%2C+C">Constantinos Charalambous</a>, <a href="/search/?searchtype=author&query=Kedar%2C+S">Sharon Kedar</a>, <a href="/search/?searchtype=author&query=Lorenz%2C+R+D">Ralph D. Lorenz</a>, <a href="/search/?searchtype=author&query=Marusiak%2C+A+G">Angela G. Marusiak</a>, <a href="/search/?searchtype=author&query=McClean%2C+J+B">John B. McClean</a>, <a href="/search/?searchtype=author&query=Nunn%2C+C">Ceri Nunn</a>, <a href="/search/?searchtype=author&query=St%C3%A4hler%2C+S+C">Simon C. St盲hler</a>, <a href="/search/?searchtype=author&query=Stott%2C+A+E">Alexander E. Stott</a>, <a href="/search/?searchtype=author&query=Warren%2C+T">Tristram Warren</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2003.08959v1-abstract-short" style="display: inline;"> Before deploying to the surface of Mars, the short-period (SP) seismometer of the InSight mission operated on deck for a total of 48 hours. This dataset can be used to understand how deck-mounted seismometers can be used in future landed missions to Mars, Europa, and other planetary bodies. While operating on deck, the SP seismometer showed signals comparable to the Viking-2 seismometer near 3 Hz… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2003.08959v1-abstract-full').style.display = 'inline'; document.getElementById('2003.08959v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2003.08959v1-abstract-full" style="display: none;"> Before deploying to the surface of Mars, the short-period (SP) seismometer of the InSight mission operated on deck for a total of 48 hours. This dataset can be used to understand how deck-mounted seismometers can be used in future landed missions to Mars, Europa, and other planetary bodies. While operating on deck, the SP seismometer showed signals comparable to the Viking-2 seismometer near 3 Hz where the sensitivity of the Viking instrument peaked. Wind sensitivity showed similar patterns to the Viking instrument, although amplitudes on InSight were ~80% larger for a given wind velocity. However, during the low wind evening hours the instrument noise levels at frequencies between 0.1 and 1 Hz were comparable to quiet stations on Earth, although deployment to the surface below the Wind and Thermal Shield lowered installation noise by roughly 40 dB in acceleration power. With the observed noise levels and estimated seismicity rates for Mars, detection probability for quakes for a deck-mounted instrument are low enough that up to years of on-deck recordings may be necessary to observe an event. Because the noise is dominated by wind acting on the lander, though, deck-mounted seismometers may be more practical for deployment on airless bodies, and it is important to evaluate the seismicity of the target body and the specific design of the lander. Detection probabilities for operation on Europa reach over 99% for some proposed seismicity models for a similar duration of operation if noise levels are comparable to low-wind time periods on Mars. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2003.08959v1-abstract-full').style.display = 'none'; document.getElementById('2003.08959v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 19 March, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">20 pages, 7 figures, accepted to Journal of Geophysical Research: Planets</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1907.02615">arXiv:1907.02615</a> <span> [<a href="https://arxiv.org/pdf/1907.02615">pdf</a>, <a href="https://arxiv.org/format/1907.02615">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Earth and Planetary Astrophysics">astro-ph.EP</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1007/s00159-019-0117-5">10.1007/s00159-019-0117-5 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Small Solar System Bodies as granular media </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Hestroffer%2C+D">D. Hestroffer</a>, <a href="/search/?searchtype=author&query=S%C3%A1nchez%2C+P">P. S谩nchez</a>, <a href="/search/?searchtype=author&query=Staron%2C+L">L. Staron</a>, <a href="/search/?searchtype=author&query=Bagatin%2C+A+C">A. Campo Bagatin</a>, <a href="/search/?searchtype=author&query=Eggl%2C+S">S. Eggl</a>, <a href="/search/?searchtype=author&query=Losert%2C+W">W. Losert</a>, <a href="/search/?searchtype=author&query=Murdoch%2C+N">N. Murdoch</a>, <a href="/search/?searchtype=author&query=Opsomer%2C+E">E. Opsomer</a>, <a href="/search/?searchtype=author&query=Radjai%2C+F">F. Radjai</a>, <a href="/search/?searchtype=author&query=Richardson%2C+D+C">D. C. Richardson</a>, <a href="/search/?searchtype=author&query=Salazar%2C+M">M. Salazar</a>, <a href="/search/?searchtype=author&query=Scheeres%2C+D+J">D. J. Scheeres</a>, <a href="/search/?searchtype=author&query=Schwartz%2C+S">S. Schwartz</a>, <a href="/search/?searchtype=author&query=Taberlet%2C+N">N. Taberlet</a>, <a href="/search/?searchtype=author&query=Yano%2C+H">H. Yano</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1907.02615v1-abstract-short" style="display: inline;"> Asteroids and other Small Solar System Bodies (SSSBs) are of high general and scientific interest in many aspects. The origin, formation, and evolution of our Solar System (and other planetary systems) can be better understood by analysing the constitution and physical properties of small bodies in the Solar System. Currently, two space missions (Hayabusa2, OSIRIS-REx) have recently arrived at the… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1907.02615v1-abstract-full').style.display = 'inline'; document.getElementById('1907.02615v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1907.02615v1-abstract-full" style="display: none;"> Asteroids and other Small Solar System Bodies (SSSBs) are of high general and scientific interest in many aspects. The origin, formation, and evolution of our Solar System (and other planetary systems) can be better understood by analysing the constitution and physical properties of small bodies in the Solar System. Currently, two space missions (Hayabusa2, OSIRIS-REx) have recently arrived at their respective targets and will bring a sample of the asteroids back to Earth. Other small body missions have also been selected by, or proposed to, space agencies. The threat posed to our planet by near-Earth objects (NEOs) is also considered at the international level, and this has prompted dedicated research on possible mitigation techniques. The DART mission, for example, will test the kinetic impact technique. Even ideas for industrial exploitation have risen during the last years. Lastly, the origin of water and life on Earth appears to be connected to asteroids. Hence, future space mission projects will undoubtedly target some asteroids or other SSSBs. In all these cases and research topics, specific knowledge of the structure and mechanical behaviour of the surface as well as the bulk of those celestial bodies is crucial. In contrast to large telluric planets and dwarf planets, a large proportion of such small bodies is believed to consist of gravitational aggregates ('rubble piles') with no -- or low -- internal cohesion, with varying macro-porosity and surface properties (from smooth regolith covered terrain, to very rough collection of boulders), and varying topography (craters, depressions, ridges) [...]. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1907.02615v1-abstract-full').style.display = 'none'; document.getElementById('1907.02615v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 4 July, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2019. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">This is a pre-print version of an article to be published in AARv, and available online at https://rdcu.be/bHM9E</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1710.10191">arXiv:1710.10191</a> <span> [<a href="https://arxiv.org/pdf/1710.10191">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Earth and Planetary Astrophysics">astro-ph.EP</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1016/j.asr.2017.10.021">10.1016/j.asr.2017.10.021 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> CASTAway: An Asteroid Main Belt Tour and Survey </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Bowles%2C+N+E">N. E. Bowles</a>, <a href="/search/?searchtype=author&query=Snodgrass%2C+C">C. Snodgrass</a>, <a href="/search/?searchtype=author&query=Gibbings%2C+A">A Gibbings</a>, <a href="/search/?searchtype=author&query=Sanchez%2C+J+P">J. P. Sanchez</a>, <a href="/search/?searchtype=author&query=Arnold%2C+J+A">J. A. Arnold</a>, <a href="/search/?searchtype=author&query=Eccleston%2C+P">P. Eccleston</a>, <a href="/search/?searchtype=author&query=Andert%2C+T">T. Andert</a>, <a href="/search/?searchtype=author&query=Probst%2C+A">A. Probst</a>, <a href="/search/?searchtype=author&query=Naletto%2C+G">G. Naletto</a>, <a href="/search/?searchtype=author&query=Vandaele%2C+A+C">A. C. Vandaele</a>, <a href="/search/?searchtype=author&query=de+Leon%2C+J">J. de Leon</a>, <a href="/search/?searchtype=author&query=Nathues%2C+A">A. Nathues</a>, <a href="/search/?searchtype=author&query=Thomas%2C+I+R">I. R. Thomas</a>, <a href="/search/?searchtype=author&query=Thomas%2C+N">N. Thomas</a>, <a href="/search/?searchtype=author&query=Jorda%2C+L">L. Jorda</a>, <a href="/search/?searchtype=author&query=Da+Deppo%2C+V">V. Da Deppo</a>, <a href="/search/?searchtype=author&query=Haack%2C+H">H. Haack</a>, <a href="/search/?searchtype=author&query=Green%2C+S+F">S. F. Green</a>, <a href="/search/?searchtype=author&query=Carry%2C+B">B. Carry</a>, <a href="/search/?searchtype=author&query=Hanna%2C+K+L+D">K. L. Donaldson Hanna</a>, <a href="/search/?searchtype=author&query=Jorgensen%2C+J+L">J. Leif Jorgensen</a>, <a href="/search/?searchtype=author&query=Kereszturi%2C+A">A. Kereszturi</a>, <a href="/search/?searchtype=author&query=DeMeo%2C+F+E">F. E. DeMeo</a>, <a href="/search/?searchtype=author&query=Patel%2C+M+R">M. R. Patel</a>, <a href="/search/?searchtype=author&query=Davies%2C+J+K">J. K. Davies</a> , et al. (20 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1710.10191v1-abstract-short" style="display: inline;"> CASTAway is a mission concept to explore our Solar System's main asteroid belt. Asteroids and comets provide a window into the formation and evolution of our Solar System and the composition of these objects can be inferred from space-based remote sensing using spectroscopic techniques. Variations in composition across the asteroid populations provide a tracer for the dynamical evolution of the So… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1710.10191v1-abstract-full').style.display = 'inline'; document.getElementById('1710.10191v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1710.10191v1-abstract-full" style="display: none;"> CASTAway is a mission concept to explore our Solar System's main asteroid belt. Asteroids and comets provide a window into the formation and evolution of our Solar System and the composition of these objects can be inferred from space-based remote sensing using spectroscopic techniques. Variations in composition across the asteroid populations provide a tracer for the dynamical evolution of the Solar System. The mission combines a long-range (point source) telescopic survey of over 10,000 objects, targeted close encounters with 10 to 20 asteroids and serendipitous searches to constrain the distribution of smaller (e.g. 10 m) size objects into a single concept. With a carefully targeted trajectory that loops through the asteroid belt, CASTAway would provide a comprehensive survey of the main belt at multiple scales. The scientific payload comprises a 50 cm diameter telescope that includes an integrated low-resolution (R = 30 to 100) spectrometer and visible context imager, a thermal (e.g. 6 to 16 microns) imager for use during the flybys, and modified star tracker cameras to detect small (approx. 10 m) asteroids. The CASTAway spacecraft and payload have high levels of technology readiness and are designed to fit within the programmatic and cost caps for a European Space Agency medium class mission, whilst delivering a significant increase in knowledge of our Solar System. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1710.10191v1-abstract-full').style.display = 'none'; document.getElementById('1710.10191v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 27 October, 2017; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2017. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">40 pages, accepted by Advances in Space Research October 2017</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1704.05664">arXiv:1704.05664</a> <span> [<a href="https://arxiv.org/pdf/1704.05664">pdf</a>, <a href="https://arxiv.org/format/1704.05664">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Geophysics">physics.geo-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Earth and Planetary Astrophysics">astro-ph.EP</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Atmospheric and Oceanic Physics">physics.ao-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1007/s11214-017-0343-y">10.1007/s11214-017-0343-y <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Estimations of the seismic pressure noise on Mars determined from Large Eddy Simulations and demonstration of pressure decorrelation techniques for the InSight mission </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Murdoch%2C+N">Naomi Murdoch</a>, <a href="/search/?searchtype=author&query=Kenda%2C+B">Balthasar Kenda</a>, <a href="/search/?searchtype=author&query=Kawamura%2C+T">Taichi Kawamura</a>, <a href="/search/?searchtype=author&query=Spiga%2C+A">Aymeric Spiga</a>, <a href="/search/?searchtype=author&query=Lognonn%C3%A9%2C+P">Philippe Lognonn茅</a>, <a href="/search/?searchtype=author&query=Mimoun%2C+D">David Mimoun</a>, <a href="/search/?searchtype=author&query=Banerdt%2C+W+B">William B. Banerdt</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1704.05664v1-abstract-short" style="display: inline;"> The atmospheric pressure fluctuations on Mars induce an elastic response in the ground that creates a ground tilt, detectable as a seismic signal on the InSight seismometer SEIS. The seismic pressure noise is modeled using Large Eddy Simulations of the wind and surface pressure at the InSight landing site and a Green's function ground deformation approach that is subsequently validated via a detai… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1704.05664v1-abstract-full').style.display = 'inline'; document.getElementById('1704.05664v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1704.05664v1-abstract-full" style="display: none;"> The atmospheric pressure fluctuations on Mars induce an elastic response in the ground that creates a ground tilt, detectable as a seismic signal on the InSight seismometer SEIS. The seismic pressure noise is modeled using Large Eddy Simulations of the wind and surface pressure at the InSight landing site and a Green's function ground deformation approach that is subsequently validated via a detailed comparison with two other methods based on Sorrells' theory (Sorrels 1971; Sorrels et al. 1971). The horizontal acceleration as a result of the ground tilt due to the LES turbulence-induced pressure fluctuations are found to be typically ~2 - 40 nm/s^2 in amplitude, whereas the direct horizontal acceleration is two orders of magnitude smaller and is thus negligible in comparison. The vertical accelerations are found to be ~0.1 - 6 nm/s^2 in amplitude. We show that under calm conditions, a single-pressure measurement is representative of the large-scale pressure field (to a distance of several kilometers), particularly in the prevailing wind direction. However, during windy conditions, small-scale turbulence results in a reduced correlation between the pressure signals, and the single-pressure measurement becomes less representative of the pressure field. Nonetheless, the correlation between the seismic signal and the pressure signal is found to be higher for the windiest period because the seismic pressure noise reflects the atmospheric structure close to the seismometer. In the same way that we reduce the atmospheric seismic signal by making use of a pressure sensor that is part of the InSight APSS (Auxiliary Payload Sensor Suite), we also the use the synthetic noise data obtained from the LES pressure field to demonstrate a decorrelation strategy. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1704.05664v1-abstract-full').style.display = 'none'; document.getElementById('1704.05664v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 19 April, 2017; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2017. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Space Science Reviews, (), 1-27, 2017 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1702.05980">arXiv:1702.05980</a> <span> [<a href="https://arxiv.org/pdf/1702.05980">pdf</a>, <a href="https://arxiv.org/format/1702.05980">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Earth and Planetary Astrophysics">astro-ph.EP</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Soft Condensed Matter">cond-mat.soft</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Geophysics">physics.geo-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnras/stw3391">10.1093/mnras/stw3391 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> An experimental study of low-velocity impacts into granular material in reduced gravity </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Murdoch%2C+N">Naomi Murdoch</a>, <a href="/search/?searchtype=author&query=Martinez%2C+I+A">Iris Avila Martinez</a>, <a href="/search/?searchtype=author&query=Sunday%2C+C">Cecily Sunday</a>, <a href="/search/?searchtype=author&query=Zenou%2C+E">Emmanuel Zenou</a>, <a href="/search/?searchtype=author&query=Cherrier%2C+O">Olivier Cherrier</a>, <a href="/search/?searchtype=author&query=Cadu%2C+A">Alexandre Cadu</a>, <a href="/search/?searchtype=author&query=Gourinat%2C+Y">Yves Gourinat</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1702.05980v1-abstract-short" style="display: inline;"> In order to improve our understanding of landing on small bodies and of asteroid evolution, we use our novel drop tower facility to perform low-velocity (2-40 cm s^-1), shallow impact experiments of a 10 cm diameter aluminum sphere into quartz sand in low effective gravities (~0.2-1 m s^-2). Using in situ accelerometers, we measure the acceleration profile during the impacts and determine the peak… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1702.05980v1-abstract-full').style.display = 'inline'; document.getElementById('1702.05980v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1702.05980v1-abstract-full" style="display: none;"> In order to improve our understanding of landing on small bodies and of asteroid evolution, we use our novel drop tower facility to perform low-velocity (2-40 cm s^-1), shallow impact experiments of a 10 cm diameter aluminum sphere into quartz sand in low effective gravities (~0.2-1 m s^-2). Using in situ accelerometers, we measure the acceleration profile during the impacts and determine the peak accelerations, collision durations and maximum penetration depth. We find that the penetration depth scales linearly with the collision velocity but is independent of the effective gravity for the experimental range tested, and that the collision duration is independent of both the effective gravity and the collision velocity. No rebounds are observed in any of the experiments. Our low-gravity experimental results indicate that the transition from the quasi-static regime to the inertial regime occurs for impact energies two orders of magnitude smaller than in similar impact experiments under terrestrial gravity. The lower energy regime change may be due to the increased hydrodynamic drag of the surface material in our experiments, but may also support the notion that the quasi-static regime reduces as the effective gravity becomes lower. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1702.05980v1-abstract-full').style.display = 'none'; document.getElementById('1702.05980v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 20 February, 2017; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2017. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Advance Access publication: January 4 2017</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1612.04308">arXiv:1612.04308</a> <span> [<a href="https://arxiv.org/pdf/1612.04308">pdf</a>, <a href="https://arxiv.org/format/1612.04308">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Geophysics">physics.geo-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Earth and Planetary Astrophysics">astro-ph.EP</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Atmospheric and Oceanic Physics">physics.ao-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1007/s11214-016-0311-y">10.1007/s11214-016-0311-y <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Evaluating the wind-induced mechanical noise on the InSight seismometers </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Murdoch%2C+N">Naomi Murdoch</a>, <a href="/search/?searchtype=author&query=Mimoun%2C+D">David Mimoun</a>, <a href="/search/?searchtype=author&query=Garcia%2C+R+F">Raphael F. Garcia</a>, <a href="/search/?searchtype=author&query=Rapin%2C+W">Willian Rapin</a>, <a href="/search/?searchtype=author&query=Kawamuea%2C+T">Taichi Kawamuea</a>, <a href="/search/?searchtype=author&query=Lognonn%C3%A9%2C+P">Philippe Lognonn茅</a>, <a href="/search/?searchtype=author&query=Banfield%2C+D">Don Banfield</a>, <a href="/search/?searchtype=author&query=Banerdt%2C+W+B">William B. Banerdt</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1612.04308v1-abstract-short" style="display: inline;"> The SEIS (Seismic Experiment for Interior Structures) instrument onboard the InSight mission to Mars is the critical instrument for determining the interior structure of Mars, the current level of tectonic activity and the meteorite flux. Meeting the performance requirements of the SEIS instrument is vital to successfully achieve these mission objectives. Here we analyse in-situ wind measurements… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1612.04308v1-abstract-full').style.display = 'inline'; document.getElementById('1612.04308v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1612.04308v1-abstract-full" style="display: none;"> The SEIS (Seismic Experiment for Interior Structures) instrument onboard the InSight mission to Mars is the critical instrument for determining the interior structure of Mars, the current level of tectonic activity and the meteorite flux. Meeting the performance requirements of the SEIS instrument is vital to successfully achieve these mission objectives. Here we analyse in-situ wind measurements from previous Mars space missions to understand the wind environment that we are likely to encounter on Mars, and then we use an elastic ground deformation model to evaluate the mechanical noise contributions on the SEIS instrument due to the interaction between the Martian winds and the InSight lander. Lander mechanical noise maps that will be used to select the best deployment site for SEIS once the InSight lander arrives on Mars are also presented. We find the lander mechanical noise may be a detectable signal on the InSight seismometers. However, for the baseline SEIS deployment position, the noise is expected to be below the total noise requirement >97% of the time and is, therefore, not expected to endanger the InSight mission objectives. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1612.04308v1-abstract-full').style.display = 'none'; document.getElementById('1612.04308v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 13 December, 2016; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2016. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">32 pages, 16 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Space Science Reviews, November 2016 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1612.00709">arXiv:1612.00709</a> <span> [<a href="https://arxiv.org/pdf/1612.00709">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Earth and Planetary Astrophysics">astro-ph.EP</span> </div> </div> <p class="title is-5 mathjax"> ASIME 2016 White Paper: In-Space Utilisation of Asteroids: "Answers to Questions from the Asteroid Miners" </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Graps%2C+A+L">Amara L. Graps</a>, <a href="/search/?searchtype=author&query=Blondel%2C+P">Philippe Blondel</a>, <a href="/search/?searchtype=author&query=Bonin%2C+G">Grant Bonin</a>, <a href="/search/?searchtype=author&query=Britt%2C+D">Daniel Britt</a>, <a href="/search/?searchtype=author&query=Centuori%2C+S">Simone Centuori</a>, <a href="/search/?searchtype=author&query=Delbo%2C+M">Marco Delbo</a>, <a href="/search/?searchtype=author&query=Drube%2C+L">Line Drube</a>, <a href="/search/?searchtype=author&query=Duffard%2C+R">Rene Duffard</a>, <a href="/search/?searchtype=author&query=Elvis%2C+M">Martin Elvis</a>, <a href="/search/?searchtype=author&query=Faber%2C+D">Daniel Faber</a>, <a href="/search/?searchtype=author&query=Frank%2C+E">Elizabeth Frank</a>, <a href="/search/?searchtype=author&query=Galache%2C+J">JL Galache</a>, <a href="/search/?searchtype=author&query=Green%2C+S+F">Simon F. Green</a>, <a href="/search/?searchtype=author&query=Grundmann%2C+J+T">Jan Thimo Grundmann</a>, <a href="/search/?searchtype=author&query=Hsieh%2C+H">Henry Hsieh</a>, <a href="/search/?searchtype=author&query=Kereszturi%2C+A">Akos Kereszturi</a>, <a href="/search/?searchtype=author&query=Laine%2C+P">Pauli Laine</a>, <a href="/search/?searchtype=author&query=Levasseur-Regourd%2C+A">Anny-Chantal Levasseur-Regourd</a>, <a href="/search/?searchtype=author&query=Maier%2C+P">Philipp Maier</a>, <a href="/search/?searchtype=author&query=Metzger%2C+P">Philip Metzger</a>, <a href="/search/?searchtype=author&query=Michel%2C+P">Patrick Michel</a>, <a href="/search/?searchtype=author&query=Mueller%2C+M">Migo Mueller</a>, <a href="/search/?searchtype=author&query=Mueller%2C+T">Thomas Mueller</a>, <a href="/search/?searchtype=author&query=Murdoch%2C+N">Naomi Murdoch</a>, <a href="/search/?searchtype=author&query=Parker%2C+A">Alex Parker</a> , et al. (6 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1612.00709v2-abstract-short" style="display: inline;"> The aim of the Asteroid Science Intersections with In-Space Mine Engineering (ASIME) 2016 conference on September 21-22, 2016 in Luxembourg City was to provide an environment for the detailed discussion of the specific properties of asteroids, with the engineering needs of space missions that utilize asteroids. The ASIME 2016 Conference produced a layered record of discussions from the asteroid… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1612.00709v2-abstract-full').style.display = 'inline'; document.getElementById('1612.00709v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1612.00709v2-abstract-full" style="display: none;"> The aim of the Asteroid Science Intersections with In-Space Mine Engineering (ASIME) 2016 conference on September 21-22, 2016 in Luxembourg City was to provide an environment for the detailed discussion of the specific properties of asteroids, with the engineering needs of space missions that utilize asteroids. The ASIME 2016 Conference produced a layered record of discussions from the asteroid scientists and the asteroid miners to understand each other's key concerns and to address key scientific questions from the asteroid mining companies: Planetary Resources, Deep Space Industries and TransAstra. These Questions were the focus of the two day conference, were addressed by scientists inside and outside of the ASIME Conference and are the focus of this White Paper. The Questions from the asteroid mining companies have been sorted into the three asteroid science themes: 1) survey, 2) surface and 3) subsurface and 4) Other. The answers to those Questions have been provided by the scientists with their conference presentations or edited directly into an early open-access collaborative Google document (August 2016-October 2016), or inserted by A. Graps using additional reference materials. During the ASIME 2016 last two-hours, the scientists turned the Questions from the Asteroid Miners around by presenting their own key concerns: Questions from the Asteroid Scientists . These answers in this White Paper will point to the Science Knowledge Gaps (SKGs) for advancing the asteroid in-space resource utilisation domain. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1612.00709v2-abstract-full').style.display = 'none'; document.getElementById('1612.00709v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 16 January, 2017; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 2 December, 2016; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2016. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">81 pages, 18 figures. White Paper from the Asteroid Science Intersections with In-Space Mine Engineering (ASIME) 2016 conference on September 21-22, 2016 in Luxembourg City</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1611.04826">arXiv:1611.04826</a> <span> [<a href="https://arxiv.org/pdf/1611.04826">pdf</a>, <a href="https://arxiv.org/format/1611.04826">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Earth and Planetary Astrophysics">astro-ph.EP</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1063/1.4961575">10.1063/1.4961575 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A novel facility for reduced-gravity testing: a set-up for studying low-velocity collisions into granular surfaces </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Sunday%2C+C">Cecily Sunday</a>, <a href="/search/?searchtype=author&query=Murdoch%2C+N">Naomi Murdoch</a>, <a href="/search/?searchtype=author&query=Cherrier%2C+O">Olivier Cherrier</a>, <a href="/search/?searchtype=author&query=Serrano%2C+S+M">Sara Morales Serrano</a>, <a href="/search/?searchtype=author&query=Nardi%2C+C+V">Claudia Valeria Nardi</a>, <a href="/search/?searchtype=author&query=Janin%2C+T">Tristan Janin</a>, <a href="/search/?searchtype=author&query=Martinez%2C+I+A">Iris Avila Martinez</a>, <a href="/search/?searchtype=author&query=Gourinat%2C+Y">Yves Gourinat</a>, <a href="/search/?searchtype=author&query=Mimoun%2C+D">David Mimoun</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1611.04826v1-abstract-short" style="display: inline;"> This work presents an experimental design for studying low-velocity collisions into granular surfaces in low-gravity. In the experiment apparatus, reduced-gravity is simulated by releasing a free-falling projectile into a surface container with a downward acceleration less than that of Earth's gravity. The acceleration of the surface is controlled through the use of an Atwood machine, or a system… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1611.04826v1-abstract-full').style.display = 'inline'; document.getElementById('1611.04826v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1611.04826v1-abstract-full" style="display: none;"> This work presents an experimental design for studying low-velocity collisions into granular surfaces in low-gravity. In the experiment apparatus, reduced-gravity is simulated by releasing a free-falling projectile into a surface container with a downward acceleration less than that of Earth's gravity. The acceleration of the surface is controlled through the use of an Atwood machine, or a system of pulleys and counterweights. The starting height of the surface container and the initial separation distance between the projectile and surface are variable and chosen to accommodate collision velocities up to 20 cm/s and effective accelerations of ~0.1 - 1.0 m/s^2. Accelerometers, placed on the surface container and inside the projectile, provide acceleration data, while high-speed cameras capture the collision and act as secondary data sources. The experiment is built into an existing 5.5 m drop-tower frame and requires the custom design of all components, including the projectile, surface sample container, release mechanism and deceleration system. Data from calibration tests verify the efficiency of the experiment's deceleration system and provide a quantitative understanding of the performance of the Atwood system. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1611.04826v1-abstract-full').style.display = 'none'; document.getElementById('1611.04826v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 15 November, 2016; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2016. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">11 pages, 11 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Review of Scientific Instruments 87, 084504 (2016) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1511.06580">arXiv:1511.06580</a> <span> [<a href="https://arxiv.org/pdf/1511.06580">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Earth and Planetary Astrophysics">astro-ph.EP</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Methods for Astrophysics">astro-ph.IM</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Atmospheric and Oceanic Physics">physics.ao-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Geophysics">physics.geo-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Detectors">physics.ins-det</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1785/0120150133">10.1785/0120150133 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Seismometer Detection of Dust Devil Vortices by Ground Tilt </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Lorenz%2C+R+D">Ralph D. Lorenz</a>, <a href="/search/?searchtype=author&query=Kedar%2C+S">Sharon Kedar</a>, <a href="/search/?searchtype=author&query=Murdoch%2C+N">Naomi Murdoch</a>, <a href="/search/?searchtype=author&query=Lognonn%C3%A9%2C+P">Philippe Lognonn茅</a>, <a href="/search/?searchtype=author&query=Kawamura%2C+T">Taichi Kawamura</a>, <a href="/search/?searchtype=author&query=Mimoun%2C+D">David Mimoun</a>, <a href="/search/?searchtype=author&query=Banerdt%2C+W+B">W. Bruce Banerdt</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1511.06580v1-abstract-short" style="display: inline;"> We report seismic signals on a desert playa caused by convective vortices and dust devils. The long-period (10-100s) signatures, with tilts of ~10$^{-7}$ radians, are correlated with the presence of vortices, detected with nearby sensors as sharp temporary pressure drops (0.2-1 mbar) and solar obscuration by dust. We show that the shape and amplitude of the signals, manifesting primarily as horizo… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1511.06580v1-abstract-full').style.display = 'inline'; document.getElementById('1511.06580v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1511.06580v1-abstract-full" style="display: none;"> We report seismic signals on a desert playa caused by convective vortices and dust devils. The long-period (10-100s) signatures, with tilts of ~10$^{-7}$ radians, are correlated with the presence of vortices, detected with nearby sensors as sharp temporary pressure drops (0.2-1 mbar) and solar obscuration by dust. We show that the shape and amplitude of the signals, manifesting primarily as horizontal accelerations, can be modeled approximately with a simple quasi-static point-load model of the negative pressure field associated with the vortices acting on the ground as an elastic half space. We suggest the load imposed by a dust devil of diameter D and core pressure 螖Po is ~(蟺/2)螖PoD$^2$, or for a typical terrestrial devil of 5 m diameter and 2 mbar, about the weight of a small car. The tilt depends on the inverse square of distance, and on the elastic properties of the ground, and the large signals we observe are in part due to the relatively soft playa sediment and the shallow installation of the instrument. Ground tilt may be a particularly sensitive means of detecting dust devils. The simple point-load model fails for large dust devils at short ranges, but more elaborate models incorporating the work of Sorrells (1971) may explain some of the more complex features in such cases, taking the vortex winds and ground velocity into account. We discuss some implications for the InSight mission to Mars. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1511.06580v1-abstract-full').style.display = 'none'; document.getElementById('1511.06580v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 20 November, 2015; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2015. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Contributed Article for Bulletin of the Seismological Society of America, Accepted 29th August 2015</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1503.01931">arXiv:1503.01931</a> <span> [<a href="https://arxiv.org/pdf/1503.01931">pdf</a>, <a href="https://arxiv.org/format/1503.01931">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Earth and Planetary Astrophysics">astro-ph.EP</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Geophysics">physics.geo-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.2458/azu_uapress_9780816532131-ch039">10.2458/azu_uapress_9780816532131-ch039 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Asteroid Surface Geophysics </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Murdoch%2C+N">Naomi Murdoch</a>, <a href="/search/?searchtype=author&query=Sanchez%2C+P">Paul Sanchez</a>, <a href="/search/?searchtype=author&query=Schwartz%2C+S+R">Stephen R. Schwartz</a>, <a href="/search/?searchtype=author&query=Miyamoto%2C+H">Hideaki Miyamoto</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1503.01931v1-abstract-short" style="display: inline;"> The regolith-covered surfaces of asteroids preserve records of geophysical processes that have occurred both at their surfaces and sometimes also in their interiors. As a result of the unique micro-gravity environment that these bodies posses, a complex and varied geophysics has given birth to fascinating features that we are just now beginning to understand. The processes that formed such feature… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1503.01931v1-abstract-full').style.display = 'inline'; document.getElementById('1503.01931v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1503.01931v1-abstract-full" style="display: none;"> The regolith-covered surfaces of asteroids preserve records of geophysical processes that have occurred both at their surfaces and sometimes also in their interiors. As a result of the unique micro-gravity environment that these bodies posses, a complex and varied geophysics has given birth to fascinating features that we are just now beginning to understand. The processes that formed such features were first hypothesised through detailed spacecraft observations and have been further studied using theoretical, numerical and experimental methods that often combine several scientific disciplines. These multiple approaches are now merging towards a further understanding of the geophysical states of the surfaces of asteroids. In this chapter we provide a concise summary of what the scientific community has learned so far about the surfaces of these small planetary bodies and the processes that have shaped them. We also discuss the state of the art in terms of experimental techniques and numerical simulations that are currently being used to investigate regolith processes occurring on small-body surfaces and that are contributing to the interpretation of observations and the design of future space missions. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1503.01931v1-abstract-full').style.display = 'none'; document.getElementById('1503.01931v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 6 March, 2015; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2015. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">28 pages, 8 figures. Chapter to appear in the book ASTEROIDS IV, (University of Arizona Press) Space Science Series, edited by P. Michel, F. DeMeo and W. Bottke</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1503.01893">arXiv:1503.01893</a> <span> [<a href="https://arxiv.org/pdf/1503.01893">pdf</a>, <a href="https://arxiv.org/ps/1503.01893">ps</a>, <a href="https://arxiv.org/format/1503.01893">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Earth and Planetary Astrophysics">astro-ph.EP</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Geophysics">physics.geo-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1016/j.icarus.2015.02.014">10.1016/j.icarus.2015.02.014 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Micro-meteoroid seismic uplift and regolith concentration on kilometric scale asteroids </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Garcia%2C+R+F">Raphael F. Garcia</a>, <a href="/search/?searchtype=author&query=Murdoch%2C+N">Naomi Murdoch</a>, <a href="/search/?searchtype=author&query=Mimoun%2C+D">David Mimoun</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1503.01893v1-abstract-short" style="display: inline;"> Seismic shaking is an attractive mechanism to explain the destabilisation of regolith slopes and the regolith migration found on the surfaces of asteroids (Richardson et al. 2004; Miyamoto et al. 2007). Here, we use a continuum mechanics method to simulate the seismic wave propagation in an asteroid. Assuming that asteroids can be described by a cohesive core surrounded by a thin non-cohesive rego… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1503.01893v1-abstract-full').style.display = 'inline'; document.getElementById('1503.01893v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1503.01893v1-abstract-full" style="display: none;"> Seismic shaking is an attractive mechanism to explain the destabilisation of regolith slopes and the regolith migration found on the surfaces of asteroids (Richardson et al. 2004; Miyamoto et al. 2007). Here, we use a continuum mechanics method to simulate the seismic wave propagation in an asteroid. Assuming that asteroids can be described by a cohesive core surrounded by a thin non-cohesive regolith layer, our numerical simulations of vibrations induced by micro-meteoroids suggest that the surface peak ground accelerations induced by micro-meteoroid impacts may have been previously under-estimated. Our lower bound estimate of vertical accelerations induced by seismic waves is about 50 times larger than previous estimates. It suggests that impact events triggering seismic activity are more frequent than previously assumed for asteroids in the kilometric and sub-kilometric size range. The regolith lofting is also estimated by a first order ballistic approximation. Vertical displacements are small, but lofting times are long compared to the duration of the seismic signals. The regolith movement has a non-linear dependence on the distance to the impact source which is induced by the type of seismic wave generating the first movement. The implications of regolith concentration in lows of surface acceleration potential are also discussed. We suggest that the resulting surface thermal inertia variations of small fast rotators may induce an increased sensitivity of these objects to the Yarkovsky effect. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1503.01893v1-abstract-full').style.display = 'none'; document.getElementById('1503.01893v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 6 March, 2015; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2015. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Accepted for publication in Icarus</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1306.2528">arXiv:1306.2528</a> <span> [<a href="https://arxiv.org/pdf/1306.2528">pdf</a>, <a href="https://arxiv.org/ps/1306.2528">ps</a>, <a href="https://arxiv.org/format/1306.2528">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Earth and Planetary Astrophysics">astro-ph.EP</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Geophysics">physics.geo-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1016/j.icarus.2010.11.030">10.1016/j.icarus.2010.11.030 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Numerical simulations of granular dynamics. I. Hard-sphere discrete element method and tests </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Richardson%2C+D+C">Derek C. Richardson</a>, <a href="/search/?searchtype=author&query=Walsh%2C+K+J">Kevin J. Walsh</a>, <a href="/search/?searchtype=author&query=Murdoch%2C+N">Naomi Murdoch</a>, <a href="/search/?searchtype=author&query=Michel%2C+P">Patrick Michel</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1306.2528v1-abstract-short" style="display: inline;"> We present a new particle-based (discrete element) numerical method for the simulation of granular dynamics, with application to motions of particles on small solar system body and planetary surfaces. The method employs the parallel N-body tree code pkdgrav to search for collisions and compute particle trajectories. Collisions are treated as instantaneous point-contact events between rigid spheres… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1306.2528v1-abstract-full').style.display = 'inline'; document.getElementById('1306.2528v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1306.2528v1-abstract-full" style="display: none;"> We present a new particle-based (discrete element) numerical method for the simulation of granular dynamics, with application to motions of particles on small solar system body and planetary surfaces. The method employs the parallel N-body tree code pkdgrav to search for collisions and compute particle trajectories. Collisions are treated as instantaneous point-contact events between rigid spheres. Particle confinement is achieved by combining arbitrary combinations of four provided wall primitives, namely infinite plane, finite disk, infinite cylinder, and finite cylinder, and degenerate cases of these. Various wall movements, including translation, oscillation, and rotation, are supported. We provide full derivations of collision prediction and resolution equations for all geometries and motions. Several tests of the method are described, including a model granular "atmosphere" that achieves correct energy equipartition, and a series of tumbler simulations that show the expected transition from tumbling to centrifuging as a function of rotation rate. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1306.2528v1-abstract-full').style.display = 'none'; document.getElementById('1306.2528v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 11 June, 2013; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2013. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">54 manuscript pages, 8 figures including 4 in colour (online version only)</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Icarus 212 (2011) 427-437 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1306.1799">arXiv:1306.1799</a> <span> [<a href="https://arxiv.org/pdf/1306.1799">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Earth and Planetary Astrophysics">astro-ph.EP</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Soft Condensed Matter">cond-mat.soft</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1016/j.icarus.2012.03.006">10.1016/j.icarus.2012.03.006 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Numerical simulations of granular dynamics II. Particle dynamics in a shaken granular material </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Murdoch%2C+N">Naomi Murdoch</a>, <a href="/search/?searchtype=author&query=Michel%2C+P">Patrick Michel</a>, <a href="/search/?searchtype=author&query=Richardson%2C+D+C">Derek C. Richardson</a>, <a href="/search/?searchtype=author&query=Nordstrom%2C+K">Kerstin Nordstrom</a>, <a href="/search/?searchtype=author&query=Berardi%2C+C+R">Christian R. Berardi</a>, <a href="/search/?searchtype=author&query=Green%2C+S+F">Simon F. Green</a>, <a href="/search/?searchtype=author&query=Losert%2C+W">Wolfgang Losert</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1306.1799v1-abstract-short" style="display: inline;"> Surfaces of planets and small bodies of our Solar System are often covered by a layer of granular material that can range from a fine regolith to a gravel-like structure of varying depths. Therefore, the dynamics of granular materials are involved in many events occurring during planetary and small-body evolution thus contributing to their geological properties. We demonstrate that the new adapt… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1306.1799v1-abstract-full').style.display = 'inline'; document.getElementById('1306.1799v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1306.1799v1-abstract-full" style="display: none;"> Surfaces of planets and small bodies of our Solar System are often covered by a layer of granular material that can range from a fine regolith to a gravel-like structure of varying depths. Therefore, the dynamics of granular materials are involved in many events occurring during planetary and small-body evolution thus contributing to their geological properties. We demonstrate that the new adaptation of the parallel N-body hard-sphere code pkdgrav has the capability to model accurately the key features of the collective motion of bidisperse granular materials in a dense regime as a result of shaking. As a stringent test of the numerical code we investigate the complex collective ordering and motion of granular material by direct comparison with laboratory experiments. We demonstrate that, as experimentally observed, the scale of the collective motion increases with increasing small-particle additive concentration. We then extend our investigations to assess how self-gravity and external gravity affect collective motion. In our reduced-gravity simulations both the gravitational conditions and the frequency of the vibrations roughly match the conditions on asteroids subjected to seismic shaking, though real regolith is likely to be much more heterogeneous and less ordered than in our idealised simulations. We also show that collective motion can occur in a granular material under a wide range of inter-particle gravity conditions and in the absence of an external gravitational field. These investigations demonstrate the great interest of being able to simulate conditions that are to relevant planetary science yet unreachable by Earth-based laboratory experiments. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1306.1799v1-abstract-full').style.display = 'none'; document.getElementById('1306.1799v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 7 June, 2013; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2013. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">78 manuscript pages, 5 tables, 12 figures including 1 in colour (online version only)</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Icarus 219 (2012) 321-335 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1306.1798">arXiv:1306.1798</a> <span> [<a href="https://arxiv.org/pdf/1306.1798">pdf</a>, <a href="https://arxiv.org/format/1306.1798">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Soft Condensed Matter">cond-mat.soft</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Earth and Planetary Astrophysics">astro-ph.EP</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Geophysics">physics.geo-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1007/s10035-013-0395-y">10.1007/s10035-013-0395-y <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Granular Shear Flow in Varying Gravitational Environments </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Murdoch%2C+N">N. Murdoch</a>, <a href="/search/?searchtype=author&query=Rozitis%2C+B">B. Rozitis</a>, <a href="/search/?searchtype=author&query=Green%2C+S+F">S. F. Green</a>, <a href="/search/?searchtype=author&query=de+Lophem%2C+T">T-L de Lophem</a>, <a href="/search/?searchtype=author&query=Michel%2C+P">P. Michel</a>, <a href="/search/?searchtype=author&query=Losert%2C+W">W. Losert</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1306.1798v1-abstract-short" style="display: inline;"> Despite their very low surface gravities, asteroids exhibit a number of different geological processes involving granular matter. Understanding the response of this granular material subject to external forces in microgravity conditions is vital to the design of a successful asteroid sub-surface sampling mechanism, and in the interpretation of the fascinating geology on an asteroid. We have design… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1306.1798v1-abstract-full').style.display = 'inline'; document.getElementById('1306.1798v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1306.1798v1-abstract-full" style="display: none;"> Despite their very low surface gravities, asteroids exhibit a number of different geological processes involving granular matter. Understanding the response of this granular material subject to external forces in microgravity conditions is vital to the design of a successful asteroid sub-surface sampling mechanism, and in the interpretation of the fascinating geology on an asteroid. We have designed and flown a Taylor-Couette shear cell to investigate granular flow due to rotational shear forces under the conditions of parabolic flight microgravity. The experiments occur under weak compression. First, we present the technical details of the experimental design with particular emphasis on how the equipment has been specifically designed for the parabolic flight environment. Then, we investigate how a steady state granular flow induced by rotational shear forces differs in varying gravitational environments. We find that the effect of constant shearing on the granular material, in a direction perpendicular to the effective acceleration, does not seem to be strongly influenced by gravity. This means that shear bands can form in the presence of a weak gravitational field just as on Earth. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1306.1798v1-abstract-full').style.display = 'none'; document.getElementById('1306.1798v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 7 June, 2013; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2013. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">18 pages, 10 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Granular Matter (2013), Volume 15, Pages 129-137 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1306.1782">arXiv:1306.1782</a> <span> [<a href="https://arxiv.org/pdf/1306.1782">pdf</a>, <a href="https://arxiv.org/format/1306.1782">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Soft Condensed Matter">cond-mat.soft</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Earth and Planetary Astrophysics">astro-ph.EP</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Geophysics">physics.geo-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevLett.110.018307">10.1103/PhysRevLett.110.018307 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Granular Convection in Microgravity </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Murdoch%2C+N">N. Murdoch</a>, <a href="/search/?searchtype=author&query=Rozitis%2C+B">B. Rozitis</a>, <a href="/search/?searchtype=author&query=Nordstrom%2C+K">K. Nordstrom</a>, <a href="/search/?searchtype=author&query=Green%2C+S+F">S. F. Green</a>, <a href="/search/?searchtype=author&query=Michel%2C+P">P. Michel</a>, <a href="/search/?searchtype=author&query=de+Lophem%2C+T+-">T. -L. de Lophem</a>, <a href="/search/?searchtype=author&query=Losert%2C+W">W. Losert</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1306.1782v1-abstract-short" style="display: inline;"> We investigate the role of gravity on convection in a dense granular shear flow. Using a microgravity modified Taylor-Couette shear cell under the conditions of parabolic flight microgravity, we demonstrate experimentally that secondary, convective-like flows in a sheared granular material are close to zero in microgravity and enhanced under high-gravity conditions, though the primary flow fields… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1306.1782v1-abstract-full').style.display = 'inline'; document.getElementById('1306.1782v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1306.1782v1-abstract-full" style="display: none;"> We investigate the role of gravity on convection in a dense granular shear flow. Using a microgravity modified Taylor-Couette shear cell under the conditions of parabolic flight microgravity, we demonstrate experimentally that secondary, convective-like flows in a sheared granular material are close to zero in microgravity and enhanced under high-gravity conditions, though the primary flow fields are unaffected by gravity. We suggest that gravity tunes the frictional particle-particle and particle-wall interactions, which have been proposed to drive the secondary flow. In addition, the degree of plastic deformation increases with increasing gravitational forces, supporting the notion that friction is the ultimate cause. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1306.1782v1-abstract-full').style.display = 'none'; document.getElementById('1306.1782v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 7 June, 2013; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2013. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">13 pages, 6 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> PRL 110, 018307 (2013) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1306.1764">arXiv:1306.1764</a> <span> [<a href="https://arxiv.org/pdf/1306.1764">pdf</a>, <a href="https://arxiv.org/format/1306.1764">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Earth and Planetary Astrophysics">astro-ph.EP</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Geophysics">physics.geo-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1093/mnras/stt742">10.1093/mnras/stt742 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Simulating regoliths in microgravity </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/?searchtype=author&query=Murdoch%2C+N">N. Murdoch</a>, <a href="/search/?searchtype=author&query=Rozitis%2C+B">B. Rozitis</a>, <a href="/search/?searchtype=author&query=Green%2C+S+F">S. F. Green</a>, <a href="/search/?searchtype=author&query=Michel%2C+P">P. Michel</a>, <a href="/search/?searchtype=author&query=de+Lophem%2C+T">T-L. de Lophem</a>, <a href="/search/?searchtype=author&query=Losert%2C+W">W. Losert</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1306.1764v1-abstract-short" style="display: inline;"> Despite their very low surface gravities, the surfaces of asteroids and comets are covered by granular materials - regolith - that can range from a fine dust to a gravel-like structure of varying depths. Understanding the dynamics of granular materials is, therefore, vital for the interpretation of the surface geology of these small bodies and is also critical for the design and/or operations of a… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1306.1764v1-abstract-full').style.display = 'inline'; document.getElementById('1306.1764v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1306.1764v1-abstract-full" style="display: none;"> Despite their very low surface gravities, the surfaces of asteroids and comets are covered by granular materials - regolith - that can range from a fine dust to a gravel-like structure of varying depths. Understanding the dynamics of granular materials is, therefore, vital for the interpretation of the surface geology of these small bodies and is also critical for the design and/or operations of any device planned to interact with their surfaces. We present the first measurements of transient weakening of granular material after shear reversal in microgravity as well as a summary of experimental results recently published in other journals, which may have important implications for small-body surfaces. Our results suggest that the force contact network within a granular material may be weaker in microgravity, although the influence of any change in the contact network is felt by the granular material over much larger distances. This could mean that small body surfaces are even more unstable than previously imagined. However, our results also indicate that the consequences of, e.g., a meteorite impact or a spacecraft landing, may be very different depending on the impact angle and location, and depending on the prior history of the small body surface. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1306.1764v1-abstract-full').style.display = 'none'; document.getElementById('1306.1764v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 7 June, 2013; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2013. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">11 pages, 8 figures</span> </p> </li> </ol> <div class="is-hidden-tablet">  <span class="help" style="display: inline-block;"><a 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