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. 2026 March 15 [2]A grand Mayan Pyramids is shown below a starry sky highlighted by the band of the Milky Way and the planets Saturn and Jupiter. Please see the explanation for more detailed information. Equinox at the Pyramid of the Feathered Serpent Image Credit & Copyright: [3]Robert Fedez Explanation: To see the feathered serpent [4]descend the Mayan pyramid requires exquisite timing. You must visit [5]El Castillo -- in [6]Mexico's [7]Yucatán Peninsula -- near an [8]equinox. Then, during the late afternoon if the sky is clear, [9]the pyramid's own [10]shadows create triangles that merge into the famous illusion of a [11]slithering viper. Also known as the [12]Temple of Kukulkan, the impressive step-pyramid stands 30 meters tall and 55 meters wide at the base. Built up as a series of square terraces by the pre-Columbian civilization between the 9th and 12th century, [13]the structure can be used as a calendar and is noted for [14]astronomical alignments. The [15]featured composite image was captured in 2019 with [16]Jupiter and Saturn straddling the diagonal central band of our [17]Milky Way galaxy. In a few days another [18]equinox will occur -- not only at Temple of Kukulcán, but [19]all over planet Earth. Tomorrow's picture: dancing galaxy __________________________________________________________________ [20]< | [21]Archive | [22]Submissions | [23]Index | [24]Search | [25]Calendar | [26]RSS | [27]Education | [28]About APOD | [29]Discuss | [30]> __________________________________________________________________ Authors & editors: [31]Robert Nemiroff ([32]MTU) & [33]Jerry Bonnell ([34]UMCP) NASA Official: Amber Straughn [35]Specific rights apply. [36]NASA Web Privacy, [37]Accessibility, [38]Notices; A service of: [39]ASD at [40]NASA / [41]GSFC, [42]NASA Science Activation & [43]Michigan Tech. U. References 1. https://apod.nasa.gov/apod/archivepix.html 2. https://apod.nasa.gov/apod/image/2603/MayanMilkyWay_Fernandez_1600.jpg 3. https://www.instagram.com/robert_fedez/ 4. https://www.youtube.com/watch?v=Zvv9EnBuem4 5. https://en.wikipedia.org/wiki/El_Castillo,_Chichen_Itza 6. https://en.wikipedia.org/wiki/Mexico 7. https://en.wikipedia.org/wiki/Yucatán_Peninsula 8. https://apod.nasa.gov/apod/ap190320.html 9. https://www.atlasobscura.com/places/pyramid-kukulcan-chichen-itza 10. https://youtu.be/Zvv9EnBuem4 11. https://en.wikipedia.org/wiki/Quetzalcoatl 12. https://en.wikipedia.org/wiki/Chichen_Itza 13. https://www.youtube.com/watch?v=ZcAZkHjUS6s 14. https://annex.exploratorium.edu/ancientobs/chichen/HTML/alignments.html 15. https://www.instagram.com/p/DKs2JmFPxF6/ 16. https://apod.nasa.gov/apod/ap201223.html 17. https://science.nasa.gov/universe/exoplanets/our-milky-way-galaxy-how-big-is-space/ 18. https://en.wikipedia.org/wiki/Equinox 19. https://science.nasa.gov/earth/facts/ 20. https://apod.nasa.gov/apod/ap260314.html 21. https://apod.nasa.gov/apod/archivepix.html 22. https://apod.nasa.gov/apod/lib/apsubmit2015.html 23. https://apod.nasa.gov/apod/lib/aptree.html 24. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search 25. https://apod.nasa.gov/apod/calendar/allyears.html 26. https://apod.com/feed.rss 27. https://apod.nasa.gov/apod/lib/edlinks.html 28. https://apod.nasa.gov/apod/lib/about_apod.html 29. https://asterisk.apod.com/discuss_apod.php?date=260315 30. https://apod.nasa.gov/apod/ap260316.html 31. http://www.phy.mtu.edu/faculty/Nemiroff.html 32. http://www.phy.mtu.edu/ 33. https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html 34. http://www.astro.umd.edu/ 35. https://apod.nasa.gov/apod/lib/about_apod.html#srapply 36. https://www.nasa.gov/about/highlights/HP_Privacy.html 37. https://www.nasa.gov/general/accessibility/ 38. https://www.nasa.gov/privacy/ 39. https://astrophysics.gsfc.nasa.gov/ 40. https://www.nasa.gov/ 41. https://www.nasa.gov/centers/goddard/ 42. https://science.nasa.gov/learners 43. http://www.mtu.edu/