Astronomy Picture of the Day

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
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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. The exoplanet's discovery, based on publicly available data from the planet-hunting Kepler Space Telescope's extended K2 mission, was announced in 2020. But K2-315b's measured orbital period, nearly equal to the extremely popular irrational number Pi, puts the exoplanet so close to its parent star that its surface is likely very warm, baking-hot in fact. And this Pi planet is over 185 light-years away. So instead of trying to arrange for an interstellar vacation to K2-315b, there may be easier and more comfortable ways for you to celebrate Pi day on planet Earth.

Tomorrow's picture: equinox at the pyramid


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Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
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