Jupiter's Great X-Ray Spot
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.