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.

2000 June 6
See Explanation.  Clicking on the picture will download 
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A Continuous Eruption on Jupiter's Moon Io
Credit: Galileo Project, JPL, NASA

Explanation: A volcano on Jupiter's moon Io has been photographed recently during an ongoing eruption. Hot glowing lava is visible on the left on this representative-color image. A glowing landscape of plateaus and valleys covered in sulfur and silicate rock surrounds the active volcano. Many features including several of the dark spots have evolved between February 2000, when the robot spacecraft Galileo currently orbiting Jupiter took this picture, and November 1999. Io is slightly larger than Earth's Moon and is the closest large moon to Jupiter. The above image shows a region about 250 kilometers across. How the internal structure of Io creates these active volcanoes remains under investigation.

Tomorrow's picture: The Closest View of Io

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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.