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.
Dark Volcano Active on Io
Explanation: The surface of Io is changing even as we watch. The inset frame of Jupiter 's most active moon was taken by the robot spacecraft Galileo in April. Just last month the larger image was taken. The new large black spot reveals that a volcano named Pillan Patera has been erupting during the interim. A vast moonscape roughly the size of Arizona has just been covered by some dark material. What is this material? It's composition remains unknown although it is certainly different in color from the red material seen surrounding volcano Pele on the upper left.
| Date | November 10, 1997 |
|---|---|
| Credit | Credit: Galileo Project, JPL, NASA |
| Authors & editors: | Robert Nemiroff (MTU) & Jerry Bonnell (UMCP) |
| A service of: |
ASD at NASA / GSFC, NASA Science Activation & Michigan Tech. U. |