﻿ 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. 2021 August 25 IFRAME: [2]https://www.youtube.com/embed/uHhQrplIm8g?rel=0 Solar System Ball Drop Video Credit & Copyright: [3]James O'Donoghue ([4]JAXA) & [5]Rami Mandow ([6]Space Australia); Text: [7]James O'Donoghue Explanation: Does a ball drop faster on Earth, Jupiter, or Uranus? The featured animation shows a ball dropping from one kilometer high toward the surfaces of [8]famous solar system bodies, assuming no [9]air resistance. The force of [10]gravity depends on the mass of the [11]attracting object, with higher masses pulling down with [12]greater forces. But [13]gravitational force also depends on distance from the [14]center of gravity, with shorter distances causing the ball to drop faster. Combining both mass and distance, it might be surprising to see that [15]Uranus pulls the ball down slightly slower than [16]Earth, despite containing over 14 times more mass. This happens because [17]Uranus has a much lower density, which puts its cloud tops further away from its [18]center of mass. Although the [19]falling ball always speeds up, if you were on the ball you would not feel this acceleration because you would be in [20]free-fall. Of the three planets mentioned, [21]the video demonstrates a ball drops even faster on [22]Jupiter than either Earth and Uranus. Tomorrow's picture: open space __________________________________________________________________ [23]< | [24]Archive | [25]Submissions | [26]Index | [27]Search | [28]Calendar | [29]RSS | [30]Education | [31]About APOD | [32]Discuss | [33]> __________________________________________________________________ Authors & editors: [34]Robert Nemiroff ([35]MTU) & [36]Jerry Bonnell ([37]UMCP) NASA Official: Phillip Newman [38]Specific rights apply. [39]NASA Web Privacy Policy and Important Notices A service of: [40]ASD at [41]NASA / [42]GSFC & [43]Michigan Tech. U. References 1. https://apod.nasa.gov/apod/archivepix.html 2. https://www.youtube.com/embed/uHhQrplIm8g?rel=0 3. https://www.youtube.com/user/jayphys85/about 4. https://global.jaxa.jp/ 5. https://twitter.com/CosmicRami 6. https://spaceaustralia.com/ 7. https://jamesodonoghue.wixsite.com/home 8. https://nssdc.gsfc.nasa.gov/planetary/factsheet/ 9. https://www.grc.nasa.gov/www/k-12/airplane/falling.html 10. https://spaceplace.nasa.gov/what-is-gravity/en/ 11. https://m.media-amazon.com/images/I/41NxxwsUPCL.jpg 12. https://phet.colorado.edu/sims/html/gravity-force-lab/latest/gravity-force-lab_en.html 13. https://en.wikipedia.org/wiki/Gravity 14. https://www.grc.nasa.gov/www/k-12/airplane/cg.html 15. https://solarsystem.nasa.gov/planets/uranus/overview/ 16. https://apod.nasa.gov/apod/ap100713.html 17. https://solarsystem.nasa.gov/planets/uranus/by-the-numbers/ 18. https://study.com/academy/lesson/understanding-the-center-of-mass-center-of-gravity.html 19. http://www.stefanom.org/spc/game.php 20. https://www.grc.nasa.gov/www/k-12/airplane/ffall.html 21. https://youtu.be/oIMMZl4n-uk 22. https://apod.nasa.gov/apod/ap190205.html 23. https://apod.nasa.gov/apod/ap210824.html 24. https://apod.nasa.gov/apod/archivepix.html 25. https://apod.nasa.gov/apod/lib/apsubmit2015.html 26. https://apod.nasa.gov/apod/lib/aptree.html 27. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search 28. https://apod.nasa.gov/apod/calendar/allyears.html 29. https://apod.nasa.gov/apod.rss 30. https://apod.nasa.gov/apod/lib/edlinks.html 31. https://apod.nasa.gov/apod/lib/about_apod.html 32. http://asterisk.apod.com/discuss_apod.php?date=210825 33. https://apod.nasa.gov/apod/ap210826.html 34. http://www.phy.mtu.edu/faculty/Nemiroff.html 35. http://www.phy.mtu.edu/ 36. https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html 37. http://www.astro.umd.edu/ 38. https://apod.nasa.gov/apod/lib/about_apod.html#srapply 39. https://www.nasa.gov/about/highlights/HP_Privacy.html 40. https://astrophysics.gsfc.nasa.gov/ 41. https://www.nasa.gov/ 42. https://www.nasa.gov/centers/goddard/ 43. http://www.mtu.edu/