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<!doctype html> <html> <head> <title>Astronomy Picture of the Day </title>  <meta name="orgcode" content="661"> <meta name="rno" content="amber.n.straughn"> <meta name="content-owner" content="Jerry.T.Bonnell.1"> <meta name="webmaster" content="michael.arida"> <meta name="description" content="A different astronomy and space science related image is featured each day, along with a brief explanation.">  <meta name=viewport content="width=device-width, initial-scale=1"> <meta name="keywords" content="earthshine, planetshine, da vinci"> <meta name="keywords" content="m81, m82, ngc 3077, galaxy merger, ifn">  <script id="_fed_an_ua_tag" src="//dap.digitalgov.gov/Universal-Federated-Analytics-Min.js?agency=NASA"> </script> </head> <body BGCOLOR="#F4F4FF" text="#000000" link="#0000FF" vlink="#7F0F9F" alink="#FF0000"> <center> <h1> Astronomy Picture of the Day </h1> <a href="archivepix.html">Discover the cosmos!</a> Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2025 April 10 <a href="image/2504/38h_M81-group_Jpeg.jpeg"> <IMG SRC="image/2504/38h_M81-group_1024.jpeg" alt="See Explanation. Clicking on the picture will download the highest resolution version available." style="max-width:100%"></a> </center> <center> 38 Hours with the M81 Group Image Credit & <a href="lib/about_apod.html#srapply">Copyright</a>: <a href="https://app.astrobin.com/u/Daniel_Yang_K.#gallery">Daniel Yang K.</a> </center> Explanation: From a garden on planet Earth, 38 hours of exposure with a camera and small telescope produced <a href="https://app.astrobin.com/u/Daniel_Yang_K.?i=ldzdz7#gallery">this cosmic photo</a> of the M81 galaxy group. In fact, the group's dominant galaxy M81 is near the center of the frame sporting grand spiral arms and a bright yellow core. Also known as Bode's galaxy, M81 itself spans some 100,000 light-years. Near the top is cigar-shaped <a href="ap190723.html">irregular galaxy M82</a>. The pair have been locked in gravitational combat for a billion years. <a href="https://phys.org/news/2019-11-astronomers-stellar-halo.html">Gravity from each galaxy</a> has profoundly affected the other during a series of cosmic close encounters. Their last go-round lasted about 100 million years and likely raised density waves rippling around M81, resulting in massive star forming regions arrayed along <a href="ap250327.html">M81</a>'s spiral arms. <a href="https://hubblesite.org/contents/news-releases/2001/news-2001-08.html">M82</a> was left with violent star forming regions too, and colliding gas clouds so energetic that the galaxy <a href="https://chandra.harvard.edu/photo/2006/m82/">glows in X-rays</a>. In the next few billion years, their continuing gravitational encounters will result in a merger, and a <a href="https://science.nasa.gov/asset/hubble/collision-scenario-for-milky-way-and-andromeda-galaxy-encounter/">single galaxy will remain</a>. Another group member, NGC 3077 is below and left of the large spiral M81. Far far away, about 12 million light-years distant the M81 group galaxies are seen toward the northern constellation Ursa Major (the Great Bear). But in the closer foreground the wide-field image is filled with integrated flux nebulae whose faint, <a href="ap160428.html">dusty interstellar clouds</a> reflect starlight above the plane of our own Milky Way galaxy. <center> Tomorrow's picture: a matinee <hr> <a href="ap250409.html"><</a> | <a href="archivepix.html">Archive</a> | <a href="lib/apsubmit2015.html">Submissions</a> | <a href="lib/aptree.html">Index</a> | <a href="https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search">Search</a> | <a href="calendar/allyears.html">Calendar</a> | <a href="/apod.rss">RSS</a> | <a href="lib/edlinks.html">Education</a> | <a href="lib/about_apod.html">About APOD</a> | <a href="http://asterisk.apod.com/discuss_apod.php?date=250410">Discuss</a> | <a href="ap250411.html">></a> <hr> Authors & editors: <a href="http://www.phy.mtu.edu/faculty/Nemiroff.html">Robert Nemiroff</a> (<a href="http://www.phy.mtu.edu/">MTU</a>) & <a href="https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html" >Jerry Bonnell</a> (<a href="http://www.astro.umd.edu/">UMCP</a>) NASA Official: Amber Straughn <a href="lib/about_apod.html#srapply">Specific rights apply</a>. <a href="https://www.nasa.gov/about/highlights/HP_Privacy.html">NASA Web Privacy Policy and Important Notices</a> A service of: <a href="https://astrophysics.gsfc.nasa.gov/">ASD</a> at <a href="https://www.nasa.gov/">NASA</a> / <a href="https://www.nasa.gov/centers/goddard/">GSFC</a>, <a href="https://science.nasa.gov/learners">NASA Science Activation</a> & <a href="http://www.mtu.edu/">Michigan Tech. U.</a> </center> </body> </html>