¿ 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 August 23 [2]See Explanation. Clicking on the picture will download the highest resolution version available. The Helix Nebula from Blanco and Hubble Image Credit: [3]C. R. O'Dell, ([4]Vanderbilt) et al. [5]ESA, [6]NOAO, [7]NASA Explanation: How did a star create the [8]Helix nebula? The shapes of [9]planetary nebula like the [10]Helix are important because they likely hold clues to how stars like the [11]Sun end their lives. Observations by the orbiting [12]Hubble Space Telescope and the [13]4-meter Blanco Telescope in [14]Chile, however, have shown the [15]Helix is not really a [16]simple helix. Rather, it incorporates two [17]nearly perpendicular disks as well as arcs, shocks, and even [18]features not well understood. Even so, many strikingly geometric symmetries remain. How a single [19]Sun-like star created such beautiful yet [20]geometric complexity is a [21]topic of research. The Helix Nebula is the nearest [22]planetary nebula to Earth, lies only about 700 [23]light years away toward the constellation of [24]Aquarius, and spans about 3 light-years. Tomorrow's picture: a rounder moon __________________________________________________________________ [25]< | [26]Archive | [27]Submissions | [28]Index | [29]Search | [30]Calendar | [31]RSS | [32]Education | [33]About APOD | [34]Discuss | [35]> __________________________________________________________________ Authors & editors: [36]Robert Nemiroff ([37]MTU) & [38]Jerry Bonnell ([39]UMCP) NASA Official: Phillip Newman [40]Specific rights apply. [41]NASA Web Privacy Policy and Important Notices A service of: [42]ASD at [43]NASA / [44]GSFC & [45]Michigan Tech. U. References 1. https://apod.nasa.gov/apod/archivepix.html 2. https://apod.nasa.gov/apod/image/2008/helix_blancoHubble_6145.jpg 3. https://www.physics.vanderbilt.edu/cv/odell.html 4. https://as.vanderbilt.edu/physics/ 5. https://www.spacetelescope.org/ 6. https://www.noao.edu/ 7. https://www.nasa.gov/ 8. https://en.wikipedia.org/wiki/Helix_Nebula 9. https://apod.nasa.gov/apod/planetary_nebulae.html 10. https://apod.nasa.gov/apod/ap030510.html 11. http://solar-center.stanford.edu/interview/nemiroff.html 12. https://apod.nasa.gov/apod/ap010806.html 13. http://www.ctio.noao.edu/noao/node/9 14. https://www.cia.gov/library/publications/the-world-factbook/geos/ci.html 15. https://www.youtube.com/watch?v=r5chyJrS8RE 16. https://mathworld.wolfram.com/Helix.html 17. https://imgsrc.hubblesite.org/hu/db/2004/32/images/e/formats/web_print.jpg 18. https://ui.adsabs.harvard.edu/abs/2020MNRAS.491..758A/abstract 19. https://www.nasa.gov/sun 20. https://apod.nasa.gov/apod/ap040910.html 21. https://ui.adsabs.harvard.edu/abs/2014apn6.confE.108V/abstract 22. https://www.noao.edu/jacoby/pn_gallery.html 23. https://chandra.harvard.edu/photo/cosmic_distance.html 24. http://www.astro.wisc.edu/~dolan/constellations/constellations/Aquarius.html 25. https://apod.nasa.gov/apod/ap200822.html 26. https://apod.nasa.gov/apod/archivepix.html 27. https://apod.nasa.gov/apod/lib/apsubmit2015.html 28. https://apod.nasa.gov/apod/lib/aptree.html 29. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search 30. https://apod.nasa.gov/apod/calendar/allyears.html 31. https://apod.nasa.gov/apod.rss 32. https://apod.nasa.gov/apod/lib/edlinks.html 33. https://apod.nasa.gov/apod/lib/about_apod.html 34. http://asterisk.apod.com/discuss_apod.php?date=200823 35. https://apod.nasa.gov/apod/ap200824.html 36. http://www.phy.mtu.edu/faculty/Nemiroff.html 37. http://www.phy.mtu.edu/ 38. https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html 39. http://www.astro.umd.edu/ 40. https://apod.nasa.gov/apod/lib/about_apod.html#srapply 41. https://www.nasa.gov/about/highlights/HP_Privacy.html 42. https://astrophysics.gsfc.nasa.gov/ 43. https://www.nasa.gov/ 44. https://www.nasa.gov/centers/goddard/ 45. http://www.mtu.edu/