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 September 10 [2]A starfield surrounds a large red nebula. The nebula has many flowing waves and folds. Please see the explanation for more detailed information. The Great Lacerta Nebula Image Credit & Copyright: [3]Ian Moehring & Kevin Roylance Explanation: It is one of the largest nebulas on the sky -- why isn't it better known? Roughly the same angular size as the [4]Andromeda Galaxy, the Great Lacerta Nebula can be found toward the [5]constellation of the Lizard (Lacerta). The [6]emission nebula is difficult to see with wide-field binoculars because [7]it is so faint, but also usually [8]difficult to see with a large telescope because it is so great in angle -- spanning about three [9]degrees. The depth, breadth, [10]waves, and beauty of the nebula -- cataloged as [11]Sharpless 126 (Sh2-126) -- can best be seen and appreciated with a [12]long duration camera exposure. The featured image is one such combined exposure -- in this case taken over three nights in August through dark skies in [13]Moses Lake, [14]Washington, [15]USA. The [16]hydrogen gas in the Great Lacerta Nebula [17]glows red because it is excited by light from the bright star [18]10 Lacertae, one of the bright blue stars just to the left of the red-glowing nebula's center. Most of the stars and nebula are about 1,200 [19]light years distant. Jigsaw Universe: [20]Astronomy Puzzle of the Day Tomorrow's picture: shadow play __________________________________________________________________ [21]< | [22]Archive | [23]Submissions | [24]Index | [25]Search | [26]Calendar | [27]RSS | [28]Education | [29]About APOD | [30]Discuss | [31]> __________________________________________________________________ Authors & editors: [32]Robert Nemiroff ([33]MTU) & [34]Jerry Bonnell ([35]UMCP) NASA Official: Amber Straughn [36]Specific rights apply. [37]NASA Web Privacy, [38]Accessibility, [39]Notices; A service of: [40]ASD at [41]NASA / [42]GSFC, [43]NASA Science Activation & [44]Michigan Tech. U. References 1. https://apod.nasa.gov/apod/archivepix.html 2. https://apod.nasa.gov/apod/image/2509/GrLacerta_Moehring_5509.jpg 3. https://www.instagram.com/ianmoe66 4. https://science.nasa.gov/mission/hubble/science/explore-the-night-sky/hubble-messier-catalog/messier-31/ 5. https://astro4edu.org/resources/diagram/YQ69V022qi60/ 6. https://en.wikipedia.org/wiki/Emission_nebula 7. https://en.wikipedia.org/wiki/List_of_the_most_distant_astronomical_objects 8. https://www.reddit.com/r/pics/comments/4vi9kq/find_a_cat/ 9. https://www.geogebra.org/m/atq6mr3a 10. https://science.nasa.gov/ems/03_behaviors/ 11. https://www.astrobin.com/6egtl5/ 12. https://apod.nasa.gov/apod/ap200329.html 13. https://youtu.be/TWA_2KnNjb4 14. https://en.wikipedia.org/wiki/Washington_(state) 15. https://en.wikipedia.org/wiki/United_States 16. https://apod.nasa.gov/apod/ap161024.html 17. https://en.wikipedia.org/wiki/Hydrogen-alpha 18. https://open.spotify.com/episode/6KLAtMAMknWsqpvmMHna0C 19. https://spaceplace.nasa.gov/light-year/en/ 20. https://www.scigames.org/apps/webjigsaw2/index.php 21. https://apod.nasa.gov/apod/ap250909.html 22. https://apod.nasa.gov/apod/archivepix.html 23. https://apod.nasa.gov/apod/lib/apsubmit2015.html 24. https://apod.nasa.gov/apod/lib/aptree.html 25. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search 26. https://apod.nasa.gov/apod/calendar/allyears.html 27. https://apod.com/feed.rss 28. https://apod.nasa.gov/apod/lib/edlinks.html 29. https://apod.nasa.gov/apod/lib/about_apod.html 30. https://asterisk.apod.com/discuss_apod.php?date=250910 31. https://apod.nasa.gov/apod/ap250911.html 32. http://www.phy.mtu.edu/faculty/Nemiroff.html 33. http://www.phy.mtu.edu/ 34. https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html 35. http://www.astro.umd.edu/ 36. https://apod.nasa.gov/apod/lib/about_apod.html#srapply 37. https://www.nasa.gov/about/highlights/HP_Privacy.html 38. https://www.nasa.gov/general/accessibility/ 39. https://www.nasa.gov/privacy/ 40. https://astrophysics.gsfc.nasa.gov/ 41. https://www.nasa.gov/ 42. https://www.nasa.gov/centers/goddard/ 43. https://science.nasa.gov/learners 44. http://www.mtu.edu/