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. 2026 April 15 [2]The relatively small International Space Station sits atop the image, about to transit in front of the illuminated Moon. Please see the explanation for more detailed information. The ISS Transits the Moon Image Credit & Copyright: [3]Sébastien Borie Text: [4]Keighley Rockcliffe ([5]NASA [6]GSFC, [7]UMBC CSST, [8]CRESST II) Explanation: Nope, that is not an alien spaceship landing on the Moon! This is an image of [9]the International Space Station (ISS) as it begins to transit in front of [10]the Moon. The ISS is in [11]low-Earth orbit (LEO) where it wizzes around the Earth every 90 minutes. [12]Orbiting the Earth 16 times per day for 25 years, the ISS has photobombed many familiar celestial objects including [13]Venus, [14]Mars, [15]Saturn, and [16]the Sun. [17]Thousands of experiments led by researchers from over one hundred countries have been conducted on the ISS. [18]Growing protein crystals in low-gravity was [19]one of the first experiments onboard the ISS and continues to contribute to new medical treatments. ISS astronauts study plant growth, water recycling, human health, and more to [20]support the Artemis missions which will take humans farther than they’ve ever gone before. Next time you are out and about at night, try to [21]spot the ISS zooming across the sky! Tomorrow's picture: the night sky in Brazil __________________________________________________________________ [22]< | [23]Archive | [24]Submissions | [25]Index | [26]Search | [27]Calendar | [28]RSS | [29]Education | [30]About APOD | [31]Discuss | [32]> __________________________________________________________________ Authors & editors: [33]Robert Nemiroff ([34]MTU) & [35]Jerry Bonnell ([36]UMCP) NASA Official: Amber Straughn [37]Specific rights apply. [38]NASA Web Privacy, [39]Accessibility, [40]Notices; A service of: [41]ASD at [42]NASA / [43]GSFC, [44]NASA Science Activation & [45]Michigan Tech. U. References 1. https://apod.nasa.gov/apod/archivepix.html 2. https://apod.nasa.gov/apod/image/2604/iss_moon_transit.jpeg 3. https://www.instagram.com/_xeratus/ 4. https://kerockcliffe.com/ 5. https://science.gsfc.nasa.gov/sci/bio/keighley.e.rockcliffe 6. https://www.nasa.gov/goddard/ 7. https://csst.umbc.edu/directory/ 8. https://cresst2.umd.edu/ 9. https://www.nasa.gov/international-space-station/ 10. https://science.nasa.gov/moon/ 11. https://www.space.com/low-earth-orbit 12. https://apod.nasa.gov/apod/ap251208.html 13. https://apod.nasa.gov/apod/ap250411.html 14. https://apod.nasa.gov/apod/ap200923.html 15. https://apod.nasa.gov/apod/ap250718.html 16. https://apod.nasa.gov/apod/ap250521.html 17. https://www.nasa.gov/missions/station/iss-research/25-year-of-scientific-discovery-aboard-international-space-station/ 18. https://www.nasa.gov/missions/station/iss-research/crystallizing-proteins-in-space-helping-to-identify-potential-treatments-for-diseases/ 19. https://ntrs.nasa.gov/citations/20020024139 20. https://www.nasa.gov/missions/station/iss-research/space-station-research-contributes-to-artemis-ii/ 21. https://www.nasa.gov/spot-the-station/ 22. https://apod.nasa.gov/apod/ap260414.html 23. https://apod.nasa.gov/apod/archivepix.html 24. https://apod.nasa.gov/apod/lib/apsubmit2015.html 25. https://apod.nasa.gov/apod/lib/aptree.html 26. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search 27. https://apod.nasa.gov/apod/calendar/allyears.html 28. https://apod.com/feed.rss 29. https://apod.nasa.gov/apod/lib/edlinks.html 30. https://apod.nasa.gov/apod/lib/about_apod.html 31. https://asterisk.apod.com/discuss_apod.php?date=260415 32. https://apod.nasa.gov/apod/ap260416.html 33. http://www.phy.mtu.edu/faculty/Nemiroff.html 34. http://www.phy.mtu.edu/ 35. https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html 36. http://www.astro.umd.edu/ 37. https://apod.nasa.gov/apod/lib/about_apod.html#srapply 38. https://www.nasa.gov/about/highlights/HP_Privacy.html 39. https://www.nasa.gov/general/accessibility/ 40. https://www.nasa.gov/privacy/ 41. https://astrophysics.gsfc.nasa.gov/ 42. https://www.nasa.gov/ 43. https://www.nasa.gov/centers/goddard/ 44. https://science.nasa.gov/learners 45. http://www.mtu.edu/