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 March 24 Your browser does not support the video tag. A Gravity Map of Earth Video Credit: [2]NASA, [3]GSFC, [4]GRACE, [5]SVS Explanation: Is gravity the same over the surface of the Earth? No -- in some places you will feel slightly heavier than others. The [6]featured Earth map video shows in colors and exaggerated highs and lows where the [7]gravitational field of [8]Earth is relatively strong and weak. A low spot, where you would feel slightly lighter, can be seen just off the coast of [9]India, in blue, while a relative high occurs in the mountains of [10]Chile in [11]South America. The cause of these irregularities [12]does not always follow present surface features. Scientists hypothesize that other important factors lie in deep underground structures in [13]Earth's mantle and may be related to the [14]Earth's appearance in the [15]distant past. The [16]featured map was composed from data taken by [17]NASA's twin [18]GRACE satellites that orbited the Earth from 2002 to 2017. [19]GRACE mapped Earth's gravity by carefully tracking tiny changes in the distance between the two satellites. Tomorrow's picture: Space Eye __________________________________________________________________ [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://www.nasa.gov/ 3. https://www.nasa.gov/goddard/ 4. https://grace.jpl.nasa.gov/mission/grace/ 5. https://svs.gsfc.nasa.gov/ 6. https://svs.gsfc.nasa.gov/11234/ 7. https://grace.jpl.nasa.gov/resources/6/grace-global-gravity-animation/ 8. https://science.nasa.gov/earth/facts/ 9. https://en.wikipedia.org/wiki/India 10. https://en.wikipedia.org/wiki/Chile 11. https://en.wikipedia.org/wiki/South_America 12. https://www.reddit.com/r/pics/comments/r72p2/just_a_dog_tilting_its_head/#lightbox 13. https://en.wikipedia.org/wiki/Earth's_mantle 14. https://apod.nasa.gov/apod/ap070922.html 15. https://apod.nasa.gov/apod/ap240701.html 16. https://svs.gsfc.nasa.gov/11234/ 17. https://www.nasa.gov/ 18. https://grace.jpl.nasa.gov/mission/grace/ 19. https://grace.jpl.nasa.gov/applications/overview/ 20. https://apod.nasa.gov/apod/ap260323.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=260324 30. https://apod.nasa.gov/apod/ap260325.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/