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APOD
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.
Closeup of an Io Volcano
Explanation: In 1979, one of NASA's Voyager spacecraft made a spectacular and unexpected discovery. Io, the innermost Galilean moon of Jupiter, was covered with volcanoes and some of them were erupting! In all, Voyager 1 observed nine volcanic eruptions during its encounter with the moon. When Voyager 2 flew past four months later it was able to confirm that at least six of them were still erupting. This Voyager image of Ra Patera, a large shield volcano, shows colorful flows up to about 200 miles long emanating from the dark central volcanic vent.
For more information about volcanism on Io, see Calvin J. Hamilton's Io page
| Date | August 4, 1995 |
|---|---|
| Credit | Credit: NASA, Voyager Project, Copyright Calvin J. Hamilton |
| Authors & editors: | Robert Nemiroff (MTU) & Jerry Bonnell (UMCP) |
| A service of: |
ASD at NASA / GSFC, NASA Science Activation & Michigan Tech. U. |