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 January 9 [2]See Explanation. Clicking on the picture will download the highest resolution version available. Peculiar Galaxies of Arp 273 Image Credit & [3]Copyright: [4]Dave Doctor Explanation: The colorful, spiky stars are in the foreground of this image taken with a small telescope [5]on planet Earth. They lie well within our own [6]Milky Way Galaxy. But the two eye-catching galaxies in the frame lie far beyond the Milky Way, at a distance of over 300 million light-years. The galaxies' twisted and distorted appearance is due to mutual gravitational tides as the pair engage in close encounters. Cataloged as Arp 273 (also as [7]UGC 1810), these galaxies do look [8]peculiar, but interacting galaxies are now understood to be common in the universe. Closer to home, the large spiral Andromeda Galaxy is known to be some 2 million light-years away and [9]inexorably approaching the Milky Way. In fact the far away peculiar galaxies of Arp 273 may offer an analog of the [10]far future encounter of Andromeda and Milky Way. Repeated galaxy encounters on a cosmic timescale ultimately result in a merger into a single galaxy of stars. [11]From our perspective, the bright cores of the Arp 273 galaxies are separated by only a little over 100,000 light-years. Tomorrow's picture: pixels in space __________________________________________________________________ [12]< | [13]Archive | [14]Submissions | [15]Index | [16]Search | [17]Calendar | [18]RSS | [19]Education | [20]About APOD | [21]Discuss | [22]> __________________________________________________________________ Authors & editors: [23]Robert Nemiroff ([24]MTU) & [25]Jerry Bonnell ([26]UMCP) NASA Official: Amber Straughn [27]Specific rights apply. [28]NASA Web Privacy Policy and Important Notices A service of: [29]ASD at [30]NASA / [31]GSFC, [32]NASA Science Activation & [33]Michigan Tech. U. References 1. https://apod.nasa.gov/apod/archivepix.html 2. https://apod.nasa.gov/apod/image/2501/Image171a.jpg 3. https://apod.nasa.gov/apod/lib/about_apod.html#srapply 4. https://daveandtelescope.wordpress.com/ 5. https://daveandtelescope.wordpress.com/2025/01/08/a-rose-by-any-other-name/ 6. https://science.nasa.gov/resource/the-milky-way-galaxy/ 7. https://apod.nasa.gov/apod/ap201018.html 8. http://nedwww.ipac.caltech.edu/level5/Arp/frames.html 9. https://science.nasa.gov/missions/hubble/nasas-hubble-shows-milky-way-is-destined-for-head-on-collision/ 10. https://hubblesite.org/contents/media/images/2012/20/3028-Image.html 11. https://hubblesite.org/contents/media/images/3872-Image 12. https://apod.nasa.gov/apod/ap250108.html 13. https://apod.nasa.gov/apod/archivepix.html 14. https://apod.nasa.gov/apod/lib/apsubmit2015.html 15. https://apod.nasa.gov/apod/lib/aptree.html 16. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search 17. https://apod.nasa.gov/apod/calendar/allyears.html 18. https://apod.nasa.gov/apod.rss 19. https://apod.nasa.gov/apod/lib/edlinks.html 20. https://apod.nasa.gov/apod/lib/about_apod.html 21. http://asterisk.apod.com/discuss_apod.php?date=250109 22. https://apod.nasa.gov/apod/ap250110.html 23. http://www.phy.mtu.edu/faculty/Nemiroff.html 24. http://www.phy.mtu.edu/ 25. https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html 26. http://www.astro.umd.edu/ 27. https://apod.nasa.gov/apod/lib/about_apod.html#srapply 28. https://www.nasa.gov/about/highlights/HP_Privacy.html 29. https://astrophysics.gsfc.nasa.gov/ 30. https://www.nasa.gov/ 31. https://www.nasa.gov/centers/goddard/ 32. https://science.nasa.gov/learners 33. http://www.mtu.edu/