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 30 [2]A star filled sky shows bands of green and purple sky glow. In the foreground is a grassy field with clouds on the horizon. Most remarkably, a series of short streaks appear like a comet's tail up from the horizon toward the upper left. Please see the explanation for more detailed information. An Artificial Comet Image Credit & Copyright: [3]Wang Chao Explanation: Yes, but can your comet tail do this? No, and what you are seeing is not the [4]tail of a [5]comet. The picture features a [6]cleverly overlayed time-lapse [7]sequence of a [8]group of satellites orbiting [9]Earth together in June. Specifically, these are [10]Starlink communications satellites in [11]low Earth orbit reflecting back sunlight before sunrise to [12]Inner Mongolia, [13]China. Although the satellites appear to the [14]human eye as points, the 20-second-long camera exposures caused them to appear as short [15]streaks. Currently there are over 9000 [16]Starlinks in orbit, with more being [17]launched nearly every week. Other [18]satellite constellations are also being planned. Explore the Universe: [19]Random APOD Generator Tomorrow's picture: celestial waterfall __________________________________________________________________ [20]< | [21]Archive | [22]Submissions | [23]Index | [24]Search | [25]Calendar | [26]RSS | [27]Education | [28]About APOD | [29]Discuss | [30]> __________________________________________________________________ Authors & editors: [31]Robert Nemiroff ([32]MTU) & [33]Jerry Bonnell ([34]UMCP) NASA Official: Amber Straughn [35]Specific rights apply. [36]NASA Web Privacy, [37]Accessibility, [38]Notices; A service of: [39]ASD at [40]NASA / [41]GSFC, [42]NASA Science Activation & [43]Michigan Tech. U. References 1. https://apod.nasa.gov/apod/archivepix.html 2. https://apod.nasa.gov/apod/image/2512/ArtificialComet_Chao_3000.jpg 3. mailto: 17662361764 at 163 dot com 4. https://apod.nasa.gov/apod/ap250128.html 5. https://science.nasa.gov/solar-system/comets/ 6. https://i.ytimg.com/vi/npW2t0aDMrY/hq720.jpg 7. https://apod.nasa.gov/apod/image/2512/ArtificialComet_Chao.mp4 8. https://apod.nasa.gov/apod/ap250614.html 9. https://science.nasa.gov/earth/earth-observatory/ 10. https://starlink.com/technology 11. https://www.nasa.gov/humans-in-space/leo-economy-frequently-asked-questions/ 12. https://youtu.be/KagBk62Digg 13. https://en.wikipedia.org/wiki/China 14. https://en.wikipedia.org/wiki/Human_eye 15. https://apod.nasa.gov/apod/ap230107.html 16. https://www.nasa.gov/centers-and-facilities/ames/nasa-starling-and-spacex-starlink-improve-space-traffic-coordination/ 17. https://apod.nasa.gov/apod/ap251015.html 18. https://en.wikipedia.org/wiki/Satellite_internet_constellation 19. https://apod.nasa.gov/apod/random_apod.html 20. https://apod.nasa.gov/apod/ap251229.html 21. https://apod.nasa.gov/apod/archivepix.html 22. https://apod.nasa.gov/apod/lib/apsubmit2015.html 23. https://apod.nasa.gov/apod/lib/aptree.html 24. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search 25. https://apod.nasa.gov/apod/calendar/allyears.html 26. https://apod.com/feed.rss 27. https://apod.nasa.gov/apod/lib/edlinks.html 28. https://apod.nasa.gov/apod/lib/about_apod.html 29. https://asterisk.apod.com/discuss_apod.php?date=251230 30. https://apod.nasa.gov/apod/ap251231.html 31. http://www.phy.mtu.edu/faculty/Nemiroff.html 32. http://www.phy.mtu.edu/ 33. https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html 34. http://www.astro.umd.edu/ 35. https://apod.nasa.gov/apod/lib/about_apod.html#srapply 36. https://www.nasa.gov/about/highlights/HP_Privacy.html 37. https://www.nasa.gov/general/accessibility/ 38. https://www.nasa.gov/privacy/ 39. https://astrophysics.gsfc.nasa.gov/ 40. https://www.nasa.gov/ 41. https://www.nasa.gov/centers/goddard/ 42. https://science.nasa.gov/learners 43. http://www.mtu.edu/