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 12, 1997

Jupiter's Dry Spots
Credit Galileo Project, JPL, NASA

Explanation: Known for its spectacular images of Jupiter's moons, Io, Ganymede, Callisto, and Europa, the robot spacecraft Galileo has also aggressively explored the Jovian atmosphere. In December of 1995, Galileo's atmospheric probe descended into Jupiter's clouds and reported a surprising absence of water. It is now believed that the probe entered through one of Jupiter's dry spots, similar to the dark region in this image of the swirling Jovian cloud deck. The smallest features visible here are tens of miles in size. These dry regions appear to correspond to locations where winds converge creating downdrafts. The downdrafts generate local cloudless clearings through which Jupiter's deeper warmer layers can be glimpsed. Just as the dark areas are extremely dry, the surroundings are full of moisture. The contrast is analogous to the desert and tropics of Earth.

Tomorrow's picture: Streaming From A Black Hole

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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.