Posted: Thu, Mar 29, 2001, 2:22 PM ET (1922 GMT)
Belts of charged particles surrounding Jupiter are more powerful than previously estimated, a finding that could spell trouble for future spacecraft missions to the giant planet. Measurements taken by the Cassini spacecraft as is flew by Jupiter late last year, combined with ground-based studies, show that there are fewer high-energy, but far more lower-energy, electrons orbiting Jupiter in belts shaped by the planet's powerful magnetic field. The net result, scientists said Wednesday, is that the belts are overall more powerful and thus more hazardous to any spacecraft that would venture through them. The harshest radiation is within 300,000 kilometers of the planet, close enough not to have been a problem for Galileo, which continues to operate despite being exposed to several times the radiation it was designed to survive. The next mission slated for Jupiter, Europa Orbiter, would also avoid the harshest belts, but would still be exposed to enough radiation that shielding of key systems, such as electronics, will be required.

Related Links:

•  NASA/JPL press release