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 April 6 [2]An astronaut is seen standing on the Moon next to an instrument with the lunar lander several meters in the distance. The dark of deep space covers the top of the frame. Please see the explanation for more detailed information. Moonquakes Surprisingly Common Image Credit: [3]NASA, [4]Apollo 11 Crew Explanation: Why are there so many moonquakes? Analyses of [5]seismometers left on the moon during the [6]Apollo moon landings reveal a surprising number of [7]moonquakes occurring within 100 kilometers of the surface. In fact, 62 [8]moonquakes were detected in data recorded between 1972 and 1977. [9]Many of these moonquakes are not only strong enough to [10]move furniture in a [11]lunar apartment, but the stiff rock of the moon continues to vibrate for many minutes, significantly longer than the softer rock [12]earthquakes on [13]Earth. The cause of the moonquakes remains unknown, but a [14]leading hypothesis include [15]tidal gravity from -- and [16]relative heating by -- our Earth. Regardless of the source, [17]future moon dwellings need to be built to withstand the frequent shakings. [18]Pictured here, [19]Apollo 11 astronaut [20]Buzz Aldrin stands beside a recently deployed [21]lunar seismometer, looking back toward the [22]lunar landing module. Explore Your Universe: [23]Random APOD Generator Tomorrow's picture: yes, flocculent __________________________________________________________________ [24]< | [25]Archive | [26]Submissions | [27]Index | [28]Search | [29]Calendar | [30]RSS | [31]Education | [32]About APOD | [33]Discuss | [34]> __________________________________________________________________ Authors & editors: [35]Robert Nemiroff ([36]MTU) & [37]Jerry Bonnell ([38]UMCP) NASA Official: Amber Straughn [39]Specific rights apply. [40]NASA Web Privacy, [41]Accessibility, [42]Notices; A service of: [43]ASD at [44]NASA / [45]GSFC, [46]NASA Science Activation & [47]Michigan Tech. U. References 1. https://apod.nasa.gov/apod/archivepix.html 2. https://apod.nasa.gov/apod/image/2504/AldrinSeismometer_Apollo11_3000.jpg 3. https://www.nasa.gov/ 4. https://www.nasa.gov/history/alsj/a11/a11.html 5. https://en.wikipedia.org/wiki/Seismometer 6. https://nssdc.gsfc.nasa.gov/planetary/lunar/apolloland.html 7. https://en.wikipedia.org/wiki/Quake_(natural_phenomenon)#Moonquake 8. https://ui.adsabs.harvard.edu/abs/1977Sci...196..979T/abstract 9. https://science.nasa.gov/moon/moonquakes/ 10. https://www.youtube.com/watch?v=A75icqf9M6w 11. https://www.nasa.gov/blogs/missions/2020/10/28/lunar-living-nasas-artemis-base-camp-concept/ 12. https://earthquake.usgs.gov/earthquakes/map/ 13. http://antwrp.gsfc.nasa.gov/apod/image/0208/earthlights02_dmsp_big.jpg 14. https://ui.adsabs.harvard.edu/abs/2017JGRE..122.1487K/abstract 15. https://en.wikipedia.org/wiki/Tidal_force 16. https://i.pinimg.com/736x/21/aa/a2/21aaa23cfe7dbdd0a2201d68c94c1dbf.jpg 17. https://apod.nasa.gov/apod/ap171025.html 18. https://www.flickr.com/photos/nasacommons/9457418581/in/album-72157634973926806/ 19. https://www.nasa.gov/history/apollo-11-mission-overview/ 20. https://www.nasa.gov/former-astronaut-edwin-buzz-aldrin/ 21. https://science.nasa.gov/resource/apollo-11-seismic-experiment/ 22. https://apod.nasa.gov/apod/ap030920.html 23. https://apod.nasa.gov/apod/random_apod.html 24. https://apod.nasa.gov/apod/ap250405.html 25. https://apod.nasa.gov/apod/archivepix.html 26. https://apod.nasa.gov/apod/lib/apsubmit2015.html 27. https://apod.nasa.gov/apod/lib/aptree.html 28. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search 29. https://apod.nasa.gov/apod/calendar/allyears.html 30. https://apod.com/feed.rss 31. https://apod.nasa.gov/apod/lib/edlinks.html 32. https://apod.nasa.gov/apod/lib/about_apod.html 33. https://asterisk.apod.com/discuss_apod.php?date=250406 34. https://apod.nasa.gov/apod/ap250407.html 35. http://www.phy.mtu.edu/faculty/Nemiroff.html 36. http://www.phy.mtu.edu/ 37. https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html 38. http://www.astro.umd.edu/ 39. https://apod.nasa.gov/apod/lib/about_apod.html#srapply 40. https://www.nasa.gov/about/highlights/HP_Privacy.html 41. https://www.nasa.gov/general/accessibility/ 42. https://www.nasa.gov/privacy/ 43. https://astrophysics.gsfc.nasa.gov/ 44. https://www.nasa.gov/ 45. https://www.nasa.gov/centers/goddard/ 46. https://science.nasa.gov/learners 47. http://www.mtu.edu/