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 14 [2]See Explanation. Clicking on the picture will download the highest resolution version available. A Year for K2-315b Artist's Illustration Credit: NASA Ames/JPL-Caltech/T. Pyle, Christine Daniloff, MIT Explanation: Want to visit a planet that has 3.14 days in a year? Then plan a trip to K2-315b, an earth-sized planet orbiting around a cool, red, M dwarf star about once every 3.14 days. [3]The exoplanet's discovery, based on publicly available data from the planet-hunting [4]Kepler Space Telescope's extended K2 mission, was announced in 2020. K2-315b's measured orbital period in days is nearly equal to the [5]extremely popular [6]irrational number Pi. That [7]puts the exoplanet so close to its parent star that its surface is likely very warm, [8]baking-hot in fact. And this Pi planet is over 185 light-years away. So instead of trying to arrange for an [9]interstellar vacation to K2-315b, there may be easier and more comfortable ways for you to celebrate [10]Pi day on planet Earth. Tomorrow's picture: equinox at the pyramid __________________________________________________________________ [11]< | [12]Archive | [13]Submissions | [14]Index | [15]Search | [16]Calendar | [17]RSS | [18]Education | [19]About APOD | [20]Discuss | [21]> __________________________________________________________________ Authors & editors: [22]Robert Nemiroff ([23]MTU) & [24]Jerry Bonnell ([25]UMCP) NASA Official: Amber Straughn [26]Specific rights apply. [27]NASA Web Privacy, [28]Accessibility, [29]Notices; A service of: [30]ASD at [31]NASA / [32]GSFC, [33]NASA Science Activation & [34]Michigan Tech. U. References 1. https://apod.nasa.gov/apod/archivepix.html 2. https://apod.nasa.gov/apod/image/2603/MIT-Pi-Planet-01-PRESS.jpg 3. https://ui.adsabs.harvard.edu/abs/2020AJ....160..172N/abstract 4. https://science.nasa.gov/mission/kepler/ 5. https://science.nasa.gov/learning-resources/10-ways-to-celebrate-pi-day-with-nasa-on-march-14/#hds-sidebar-nav-9 6. https://apod.nasa.gov/htmltest/rjn_dig.html 7. https://science.nasa.gov/resource/orbits-and-keplers-laws/ 8. https://news.mit.edu/2020/earth-sized-pi-planet-0921 9. https://science.nasa.gov/exoplanets/immersive/exoplanet-travel-bureau/ 10. https://earthsky.org/human-world/pi-day-nasa-pi-day-challenge/ 11. https://apod.nasa.gov/apod/ap260313.html 12. https://apod.nasa.gov/apod/archivepix.html 13. https://apod.nasa.gov/apod/lib/apsubmit2015.html 14. https://apod.nasa.gov/apod/lib/aptree.html 15. https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search 16. https://apod.nasa.gov/apod/calendar/allyears.html 17. https://apod.com/feed.rss 18. https://apod.nasa.gov/apod/lib/edlinks.html 19. https://apod.nasa.gov/apod/lib/about_apod.html 20. https://asterisk.apod.com/discuss_apod.php?date=260314 21. https://apod.nasa.gov/apod/ap260315.html 22. http://www.phy.mtu.edu/faculty/Nemiroff.html 23. http://www.phy.mtu.edu/ 24. https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html 25. http://www.astro.umd.edu/ 26. https://apod.nasa.gov/apod/lib/about_apod.html#srapply 27. https://www.nasa.gov/about/highlights/HP_Privacy.html 28. https://www.nasa.gov/general/accessibility/ 29. https://www.nasa.gov/privacy/ 30. https://astrophysics.gsfc.nasa.gov/ 31. https://www.nasa.gov/ 32. https://www.nasa.gov/centers/goddard/ 33. https://science.nasa.gov/learners 34. http://www.mtu.edu/