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Closest rocky exoplanet

NASA’s Spitzer Space Telescope confirms the discovery of the nearest rocky planet a mere 21 light-years away

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Take the Universe With You!

First exo-aurora

Powerful aurora found beyond our solar system

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Join Astronomy's Aurora Adventure

Experience a once-in-a-lifetime northern lights tour with Astronomy magazine and TravelQuest International

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Year of Pluto

Revelations of a distant world

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Pillars of destruction

Cosmic winds erode gas and dust, stopping star formation.

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Pluto's atmosphere

New Horizons sees haze around the backlit world

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Indonesian Islands Eclipse

Explore Bali and witness a total solar eclipse in March 2016 with Astronomy magazine and TravelQuest International

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Hubble at 25

How the space telescope changed the cosmos

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Ancient mega-Earth

Kepler finds a super-Earth around a Sun-like star

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Exclusive podcast series

Editor David J. Eicher conducts extensive interviews with the world's top astrophysicists, planetary scientists, and cosmologists

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Even more mountains

Pluto's heart is home to a second range of ice mountains

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Uwingu Mars

Name a crater ... make an impact!

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Closest rocky exoplanet

NASA’s Spitzer Space Telescope confirms the discovery of the nearest rocky planet a mere 21 light-years away

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PICTURE OF THE DAYsee all »

Blue Moon

The “Blue” Moon isn’t really blue. The term comes from an old English usage that originally meant “betrayer” Moon, which was a Full Moon that appeared when it shouldn’t have. This all had to do with the church’s calculation of Lent and other religious holidays, so an extra Full Moon during the year caused some problems. The actual definition of a Blue Moon is the third Full Moon in any season that has four Full Moons. (Most seasons have only three.) These days, however, most people call the second Full Moon in a month a Blue Moon. (8-inch Celestron Schmidt-Cassegrain telescope at f/10, Canon 6D, ISO 400, 1/640-second exposure, taken July 31, 2015, from Dayton, Ohio)
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