﻿ 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. 2022 February 6 [2]The featured image shows a full face of Earth as photographed by the Apollo 17 Crew in 1972. Please see the explanation for more detailed information. Blue Marble Earth Image Credit: [3]NASA, [4]Apollo 17 Crew Explanation: Welcome to planet Earth, the third planet from a star named the Sun. The [5]Earth is shaped like a [6]sphere and [7]composed mostly of rock. Over 70 percent of the [8]Earth's surface is water. The planet has a relatively [9]thin atmosphere composed mostly of [10]nitrogen and [11]oxygen. The [12]featured picture of Earth, dubbed [13]The Blue Marble, was [14]taken from [15]Apollo 17 in 1972 and features [16]Africa and [17]Antarctica. It is thought to be one of the most [18]widely distributed photographs of any kind. [19]Earth has a single large [20]Moon that is about 1/4 of its diameter and, from the planet's surface, is seen to have almost exactly the [21]same angular size as the Sun. With its [22]abundance of liquid water, Earth supports a large [23]variety of life forms, including potentially intelligent species such as [24]dolphins and [25]humans. Please [26]enjoy your stay on planet Earth. Tomorrow's picture: galactic rain __________________________________________________________________ [27]< | [28]Archive | [29]Submissions | [30]Index | [31]Search | [32]Calendar | [33]RSS | [34]Education | [35]About APOD | [36]Discuss | [37]> __________________________________________________________________ Authors & editors: [38]Robert Nemiroff ([39]MTU) & [40]Jerry Bonnell ([41]UMCP) NASA Official: Phillip Newman [42]Specific rights apply. [43]NASA Web Privacy Policy and Important Notices A service of: [44]ASD at [45]NASA / [46]GSFC & [47]Michigan Tech. U. References 1. https://apod.nasa.gov/apod/archivepix.html 2. https://apod.nasa.gov/apod/image/2202/bluemarble_apollo17_3000.jpg 3. https://www.nasa.gov/ 4. https://www.nasa.gov/mission_pages/apollo/missions/apollo17.html 5. https://solarsystem.nasa.gov/planets/earth/in-depth/ 6. https://www.geogebra.org/m/gsXuhRrs 7. https://en.wikipedia.org/wiki/Earth#Chemical_composition 8. https://www.usgs.gov/special-topics/water-science-school/science/how-much-water-there-earth 9. https://www.nasa.gov/multimedia/imagegallery/image_feature_1529.html 10. https://periodic.lanl.gov/7.shtml 11. https://periodic.lanl.gov/8.shtml 12. https://www.nasa.gov/content/blue-marble-image-of-the-earth-from-apollo-17 13. https://en.wikipedia.org/wiki/The_Blue_Marble 14. https://apolloinrealtime.org/17/?t=005:49:47 15. https://solarsystem.nasa.gov/missions/apollo-17/in-depth/ 16. https://en.wikipedia.org/wiki/Africa 17. https://en.wikipedia.org/wiki/Antarctica 18. https://earthobservatory.nasa.gov/features/BlueMarble/BlueMarble_history.php 19. https://earthobservatory.nasa.gov/features/earth-book-2019 20. https://solarsystem.nasa.gov/moons/earths-moon/overview/ 21. https://apod.nasa.gov/apod/ap160501.html 22. https://apod.nasa.gov/apod/ap160911.html 23. https://science.nasa.gov/solar-system/big-questions/how-did-life-begin-and-evolve-earth-and-has-it-evolved-elsewhere-solar-system 24. https://us.whales.org/whales-dolphins/how-intelligent-are-whales-and-dolphins/ 25. https://apod.nasa.gov/apod/ap190818.html 26. https://www.jwj.org/wp-content/uploads/2015/01/happy-kitten-kittens-5890512-1600-12001-1024x768.jpg 27. https://apod.nasa.gov/apod/ap220205.html 28. https://apod.nasa.gov/apod/archivepix.html 29. https://apod.nasa.gov/apod/lib/apsubmit2015.html 30. https://apod.nasa.gov/apod/lib/aptree.html 31. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search 32. https://apod.nasa.gov/apod/calendar/allyears.html 33. https://apod.nasa.gov/apod.rss 34. https://apod.nasa.gov/apod/lib/edlinks.html 35. https://apod.nasa.gov/apod/lib/about_apod.html 36. http://asterisk.apod.com/discuss_apod.php?date=220206 37. https://apod.nasa.gov/apod/ap220207.html 38. http://www.phy.mtu.edu/faculty/Nemiroff.html 39. http://www.phy.mtu.edu/ 40. https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html 41. http://www.astro.umd.edu/ 42. https://apod.nasa.gov/apod/lib/about_apod.html#srapply 43. https://www.nasa.gov/about/highlights/HP_Privacy.html 44. https://astrophysics.gsfc.nasa.gov/ 45. https://www.nasa.gov/ 46. https://www.nasa.gov/centers/goddard/ 47. http://www.mtu.edu/