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. 2023 September 12 [2]See Explanation. Clicking on the picture will download the highest resolution version available. Galaxy Cluster Abell 370 and Beyond Image Credit: [3]NASA, [4]ESA, Jennifer Lotz and the [5]HFF Team ([6]STScI) Explanation: Some 4 billion light-years away, massive galaxy cluster Abell 370 is captured in this sharp [7]Hubble Space Telescope snapshot. The cluster of galaxies only appears to be dominated by two giant elliptical galaxies and infested with faint arcs. In reality, the fainter, scattered bluish arcs, along with the [8]dramatic dragon arc below and left of center, are images of galaxies that lie far beyond Abell 370. About twice as distant, their otherwise undetected light is magnified and distorted by the cluster's enormous gravitational mass, overwhelmingly dominated by unseen [9]dark matter. Providing a [10]tantalizing glimpse of galaxies in the early universe, the effect is known as gravitational [11]lensing. A consequence of warped [12]spacetime, lensing was predicted by Einstein almost a century ago. [13]Far beyond the spiky foreground Milky Way star at lower right, Abell 370 is seen toward the constellation Cetus, the Sea Monster. It was the last of six galaxy clusters imaged in the [14]Frontier Fields project. Tomorrow's picture: partly hidden __________________________________________________________________ [15]< | [16]Archive | [17]Submissions | [18]Index | [19]Search | [20]Calendar | [21]RSS | [22]Education | [23]About APOD | [24]Discuss | [25]> __________________________________________________________________ Authors & editors: [26]Robert Nemiroff ([27]MTU) & [28]Jerry Bonnell ([29]UMCP) NASA Official: Phillip Newman [30]Specific rights apply. [31]NASA Web Privacy Policy and Important Notices A service of: [32]ASD at [33]NASA / [34]GSFC, [35]NASA Science Activation & [36]Michigan Tech. U. References 1. https://apod.nasa.gov/apod/archivepix.html 2. https://apod.nasa.gov/apod/image/2309/STSCI-HST-abell370_1797x2000.jpg 3. https://www.nasa.gov/ 4. http://www.spacetelescope.org/ 5. https://frontierfields.org/about/ 6. http://www.stsci.edu/portal/ 7. https://hubblesite.org/contents/media/images/2017/20/4024-Image.html 8. https://apod.nasa.gov/apod/ap160828.html 9. https://en.wikipedia.org/wiki/Dark_matter#Galaxy_clusters 10. http://webbtelescope.org/ 11. https://apod.nasa.gov/apod/ap151127.html 12. http://www.black-holes.org/ 13. https://hubblesite.org/contents/media/videos/2017/20/953-Video.html 14. https://frontierfields.org/ 15. https://apod.nasa.gov/apod/ap230911.html 16. https://apod.nasa.gov/apod/archivepix.html 17. https://apod.nasa.gov/apod/lib/apsubmit2015.html 18. https://apod.nasa.gov/apod/lib/aptree.html 19. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search 20. https://apod.nasa.gov/apod/calendar/allyears.html 21. https://apod.nasa.gov/apod.rss 22. https://apod.nasa.gov/apod/lib/edlinks.html 23. https://apod.nasa.gov/apod/lib/about_apod.html 24. http://asterisk.apod.com/discuss_apod.php?date=230912 25. https://apod.nasa.gov/apod/ap230913.html 26. http://www.phy.mtu.edu/faculty/Nemiroff.html 27. http://www.phy.mtu.edu/ 28. https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html 29. http://www.astro.umd.edu/ 30. https://apod.nasa.gov/apod/lib/about_apod.html#srapply 31. https://www.nasa.gov/about/highlights/HP_Privacy.html 32. https://astrophysics.gsfc.nasa.gov/ 33. https://www.nasa.gov/ 34. https://www.nasa.gov/centers/goddard/ 35. https://science.nasa.gov/learners 36. http://www.mtu.edu/