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.

2002 March 1
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Jupiter's Great X-Ray Spot
Credit: X-ray Image: R.Gladstone (SwRI), et al., Optical Image: Cassini Imaging Team, NASA

Explanation: The Solar System's largest planet, gas giant Jupiter, is famous for its swirling Great Red Spot. In the right hand panel above, the familiar giant planet with storm system and cloud bands is shown in an optical image from the passing Cassini spacecraft. In the left hand panel, a false-color image from the orbiting Chandra Observatory presents a corresponding x-ray view of Jupiter. The Chandra image shows clearly, for the first time, x-ray spots and auroral x-ray emission from the poles. The x-ray spot dominating the emission from Jupiter's north pole (top) is perhaps as surprising for astronomers today as the Great Red Spot once was. Confounding previous theories, the x-ray spot is too far north to be associated with heavy electrically charged particles from the vicinity of volcanic moon Io. Chandra data also show that the spot's x-ray emission mysteriously pulsates over a period of about 45 minutes.

Tomorrow's picture: not a comet

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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.