Astronomy Picture of the Day [1]Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2025 December 11 [2]See Explanation. Clicking on the picture will download the highest resolution version available. Galaxies in the River Image Credit & [3]Copyright: [4]Vikas Chander Explanation: Large galaxies grow by eating small ones. [5]Even our own galaxy engages in a sort of galactic [6]cannibalism, absorbing small galaxies that are too close and are [7]captured by the Milky Way's gravity. In fact, the [8]practice is common in the universe and illustrated by this striking pair of interacting galaxies from the banks of the southern constellation [9]Eridanus, [10]The River. Located over 50 million light years away, the large, distorted spiral NGC 1532 is seen locked in a gravitational struggle with dwarf galaxy NGC 1531, a struggle the smaller galaxy [11]will eventually lose. Seen nearly edge-on, [12]in this sharp image spiral NGC 1532 spans about 100,000 light-years. The NGC 1532/1531 pair is thought to be similar to the well-studied system of face-on spiral and small companion [13]known as M51. Tomorrow's picture: fox fires __________________________________________________________________ [14]< | [15]Archive | [16]Submissions | [17]Index | [18]Search | [19]Calendar | [20]RSS | [21]Education | [22]About APOD | [23]Discuss | [24]> __________________________________________________________________ Authors & editors: [25]Robert Nemiroff ([26]MTU) & [27]Jerry Bonnell ([28]UMCP) NASA Official: Amber Straughn [29]Specific rights apply. [30]NASA Web Privacy, [31]Accessibility, [32]Notices; A service of: [33]ASD at [34]NASA / [35]GSFC, [36]NASA Science Activation & [37]Michigan Tech. U. References 1. https://apod.nasa.gov/apod/archivepix.html 2. https://apod.nasa.gov/apod/image/2512/NGC1532.jpg 3. https://apod.nasa.gov/apod/lib/about_apod.html#srapply 4. https://www.instagram.com/vikaschanderastrophotography/ 5. https://apod.nasa.gov/apod/ap050529.html 6. http://www.cosmotography.com/images/galaxy_cannibalism.html 7. http://arxiv.org/abs/astro-ph/0407566 8. https://www.nasa.gov/image-feature/goddard/2017/hubble-catches-a-galaxy-duo-by-the-hare 9. http://www.hawastsoc.org/deepsky/eri/index.html 10. https://apod.nasa.gov/apod/ap160102.html 11. https://apod.nasa.gov/apod/ap080619.html 12. https://app.astrobin.com/u/vikaschander@rolexhosiery.com?i=n268cv#gallery 13. https://apod.nasa.gov/apod/ap220902.html 14. https://apod.nasa.gov/apod/ap251210.html 15. https://apod.nasa.gov/apod/archivepix.html 16. https://apod.nasa.gov/apod/lib/apsubmit2015.html 17. https://apod.nasa.gov/apod/lib/aptree.html 18. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search 19. https://apod.nasa.gov/apod/calendar/allyears.html 20. https://apod.com/feed.rss 21. https://apod.nasa.gov/apod/lib/edlinks.html 22. https://apod.nasa.gov/apod/lib/about_apod.html 23. https://asterisk.apod.com/discuss_apod.php?date=251211 24. https://apod.nasa.gov/apod/ap251212.html 25. http://www.phy.mtu.edu/faculty/Nemiroff.html 26. http://www.phy.mtu.edu/ 27. https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html 28. http://www.astro.umd.edu/ 29. https://apod.nasa.gov/apod/lib/about_apod.html#srapply 30. https://www.nasa.gov/about/highlights/HP_Privacy.html 31. https://www.nasa.gov/general/accessibility/ 32. https://www.nasa.gov/privacy/ 33. https://astrophysics.gsfc.nasa.gov/ 34. https://www.nasa.gov/ 35. https://www.nasa.gov/centers/goddard/ 36. https://science.nasa.gov/learners 37. http://www.mtu.edu/