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Jupiter Hot Spot Makes Trouble For TheoryFebruary 27, 2002RELEASE: 02-34 Dolores Beasley Headquarters, Washington Phone: 202/358-1753 Steve Roy Marshall Space Flight Center, Huntsville, AL Phone: 256-544-6535 Megan Watzke Chandra X-ray Observatory Center, CfA, Cambridge, MA Phone: 617-496-7998
"The location of the X-ray hot spot effectively retires the existing explanation for Jupiter's X-ray emission, leaving us very unsure of its origin," said Randy Gladstone, of the Southwest Research Institute in San Antonio and lead author of a paper on the results in the Feb.28, 2002 issue of the journal Nature. "The source of ions that produce the X-rays must be a lot farther away from Jupiter than previously believed." Chandra observed Jupiter for 10 hours on Dec. 18, 2000, when NASA's Cassini spacecraft was flying by Jupiter on its way to Saturn. The X-ray observations revealed that most of the auroral X-rays come from a pulsating hot spot that appears at a fixed location near the north magnetic pole of Jupiter. Bright infrared and ultraviolet emissions have also been detected from this region in the past. The X-rays were observed to pulsate with a period of 45 minutes, similar to the period of high-latitude radio pulsations detected by NASA's Galileo and Cassini spacecraft.
Chandra's ability to accurately determine the location of the X-rays proved this model incorrect, as ions from regions of Jupiter's magnetic field near Io cannot reach the high Jovian latitudes where most of the X-rays were observed. This result has its own problems. At the large distances required for the source of the ions - at least 30 times the radius of Jupiter - spacecraft measurements have shown that there are not nearly enough energetic oxygen and sulfur ions to account for the observed X-ray emission. One possibility is that heavy ions among the particles flowing out from the Sun as the solar wind are captured in the outer regions of Jupiter's magnetic field, then accelerated and directed toward its magnetic pole. Once captured, the ions would bounce back and forth in the magnetic field from pole to pole in an oscillating motion that might explain the pulsations. The High Resolution Camera used for the Chandra observations was built by the Smithsonian Astrophysical Observatory in Cambridge, Mass. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program, and TRW, Inc., Redondo Beach, Calif., is the prime contractor. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, Mass. [ Press Index ] [ Press Releases ] [ View other Solar System Releases ] |
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Revised: September 06, 2006
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