¿ 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. 2020 April 27 [2]See Explanation. Clicking on the picture will download the highest resolution version available. Fresh Tiger Stripes on Saturn's Enceladus Image Credit: [3]NASA, [4]ESA, [5]JPL, [6]SSI, [7]Cassini Imaging Team Explanation: How will humanity first [8]learn of extraterrestrial life? One possibility is to find it under the icy surface of Saturn's moon [9]Enceladus. A reason to think that life may exist there are long features -- dubbed tiger stripes -- that are known to be [10]spewing ice from the moon's icy interior into space. These surface cracks create clouds of fine ice particles over the moon's South Pole and create [11]Saturn's mysterious [12]E-ring. Evidence for this has come from the [13]robot Cassini spacecraft that orbited [14]Saturn from 2004 to 2017. [15]Pictured here, a high resolution image of [16]Enceladus is shown from a close flyby. The unusual surface [17]tiger stripes are shown in false-color blue. Why [18]Enceladus is active remains a mystery, as the neighboring moon [19]Mimas, approximately the same size, appears [20]quite dead. A [21]recent analysis of [22]ejected ice grains has yielded evidence that complex organic molecules exist inside Enceladus. These large carbon-rich [23]molecules bolster -- but do not prove -- that oceans under Enceladus' surface could [24]contain life. Another [25]Solar System moon that might contain [26]underground life is [27]Europa. Experts Debate: [28]How will humanity first discover ET life? Tomorrow's picture: an almost solar system __________________________________________________________________ [29]< | [30]Archive | [31]Submissions | [32]Index | [33]Search | [34]Calendar | [35]RSS | [36]Education | [37]About APOD | [38]Discuss | [39]> __________________________________________________________________ Authors & editors: [40]Robert Nemiroff ([41]MTU) & [42]Jerry Bonnell ([43]UMCP) NASA Official: Phillip Newman [44]Specific rights apply. [45]NASA Web Privacy Policy and Important Notices A service of: [46]ASD at [47]NASA / [48]GSFC & [49]Michigan Tech. U. References 1. https://apod.nasa.gov/apod/archivepix.html 2. https://apod.nasa.gov/apod/image/2004/enceladusstripes_cassini_3237.jpg 3. https://www.nasa.gov/ 4. https://www.esa.int/ 5. https://www.jpl.nasa.gov/ 6. https://www.spacescience.org/ 7. http://ciclops.org/ 8. https://apod.nasa.gov/debate/debate100th.html 9. https://solarsystem.nasa.gov/moons/saturn-moons/enceladus/in-depth/ 10. https://apod.nasa.gov/apod/ap071013.html 11. https://solarsystem.nasa.gov/planets/saturn/overview/ 12. https://apod.nasa.gov/apod/ap070327.html 13. https://solarsystem.nasa.gov/missions/cassini/the-journey/the-spacecraft/ 14. https://en.wikipedia.org/wiki/Saturn 15. https://photojournal.jpl.nasa.gov/catalog/PIA06254 16. https://solarsystem.nasa.gov/moons/saturn-moons/enceladus/in-depth/ 17. https://en.wikipedia.org/wiki/Tiger 18. https://solarsystem.nasa.gov/moons/saturn-moons/enceladus/by-the-numbers/ 19. https://apod.nasa.gov/apod/ap141021.html 20. http://www.davidpbrown.co.uk/jokes/monty-python-parrot.html 21. https://www.nasa.gov/feature/jpl/complex-organics-bubble-up-from-ocean-world-enceladus 22. https://apod.nasa.gov/apod/ap170416.html 23. https://gizmodo.com/the-discovery-of-complex-organic-molecules-on-saturn-s-1827173141 24. http://science.nasa.gov/science-news/science-at-nasa/2012/27mar_enceladus/ 25. https://solarsystem.nasa.gov/solar-system/our-solar-system/overview/ 26. http://phy.mtu.edu/debate/2020/Consolmagno100th.html 27. https://solarsystem.nasa.gov/moons/jupiter-moons/europa/overview/ 28. https://apod.nasa.gov/debate/debate100th.html 29. https://apod.nasa.gov/apod/ap200426.html 30. https://apod.nasa.gov/apod/archivepix.html 31. https://apod.nasa.gov/apod/lib/apsubmit2015.html 32. https://apod.nasa.gov/apod/lib/aptree.html 33. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search 34. https://apod.nasa.gov/apod/calendar/allyears.html 35. https://apod.nasa.gov/apod.rss 36. https://apod.nasa.gov/apod/lib/edlinks.html 37. https://apod.nasa.gov/apod/lib/about_apod.html 38. http://asterisk.apod.com/discuss_apod.php?date=200427 39. https://apod.nasa.gov/apod/ap200428.html 40. http://www.phy.mtu.edu/faculty/Nemiroff.html 41. http://www.phy.mtu.edu/ 42. https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html 43. http://www.astro.umd.edu/ 44. https://apod.nasa.gov/apod/lib/about_apod.html#srapply 45. https://www.nasa.gov/about/highlights/HP_Privacy.html 46. https://astrophysics.gsfc.nasa.gov/ 47. https://www.nasa.gov/ 48. https://www.nasa.gov/centers/goddard/ 49. http://www.mtu.edu/