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.

June 23, 1997
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Eruption on Io
Credit: J. Spencer (Lowell Obs.), WFPC2, HST, NASA

Explanation: There it goes again. Gas and rock were catapulted hundreds of kilometers into space as Jupiter's most volatile moon, Io, showed yet another impressive volcanic display in this just-released photograph by the Hubble Space Telescope. This time the culprit was Pele, a volcano thought previously inactive since photographed by the passing Voyager 1 spacecraft in 1979. The explosion is visible on Io's lower left in this false-color photograph, taken in July 1996. Io's thin atmosphere and low gravity allow volcanic plumes to rise higher than they would on Earth.

Tomorrow's picture: Antares

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Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (USRA)
NASA Technical Rep.: Jay Norris. Specific rights apply.
A service of: LHEA at NASA/ GSFC
&: Michigan Tech. U.