¿ 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 March 23 [2]The planet Mars is pictured of the Duddo Stone Circle in the UK. See Explanation. Mars over Duddo Stone Circle Image Credit & Copyright: [3]Ged Kivlehan Explanation: Why are these large stones here? One the more famous stone circles is the [4]Duddo Five Stones of [5]Northumberland, [6]England. Set in the open near the top of a modest incline, [7]a short hike across empty fields will bring you to [8]unusual [9]human [10]-sized stones that are unlike anything surrounding them. The grooved, pitted, and deeply [11]weathered surfaces of the soft [12]sandstones are consistent with being placed about 4000 years ago -- but placed for [13]reasons now unknown. The featured image -- a composite of two consecutive images taken from the same location -- was captured last October under a starry sky when the [14]Earth was passing near Mars, making the [15]red planet unusually large and bright. [16]Mars remains [17]visible at sunset, although increasingly [18]close to the horizon over the next few months. APOD via Instagram in: [19]English, [20]Indonesian, [21]Persian, and [22]Portuguese Tomorrow's picture: lightning up jupiter __________________________________________________________________ [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://apod.nasa.gov/apod/image/2103/MarsDuddo_Kivlehan_2250.jpg 3. mailto:%20gedtkay%20@at@%20yahoo%20.dot.%20co%20.dot.%20uk 4. https://en.wikipedia.org/wiki/Duddo_Five_Stones 5. https://youtu.be/3aRLHb8Wa0U 6. https://en.wikipedia.org/wiki/England 7. https://youtu.be/LyPhlCXgJ3c 8. https://youtu.be/9qnSmkJj9s4 9. https://apod.nasa.gov/apod/ap190818.html 10. https://youtu.be/9qnSmkJj9s4 11. https://youtu.be/yxKRnkrO8sA 12. https://en.wikipedia.org/wiki/Sandstone 13. https://www.northumberlandarchives.com/2020/07/13/the-duddo-stones/ 14. https://solarsystem.nasa.gov/planets/earth/overview/ 15. https://apod.nasa.gov/apod/ap201006.html 16. https://solarsystem.nasa.gov/planets/mars/overview/ 17. https://solarsystem.nasa.gov/resources/2581/whats-up-march-2021-video/ 18. https://apod.nasa.gov/apod/ap151126.html 19. https://www.instagram.com/astronomypicturesdaily/ 20. https://www.instagram.com/apod.id/ 21. https://www.instagram.com/avastarapod/ 22. https://www.instagram.com/apodbrasil/ 23. https://apod.nasa.gov/apod/ap210322.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=210323 33. https://apod.nasa.gov/apod/ap210324.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/