Magnetospheres of Jupiter and Saturn.
A series of calculations has been carried out to estimate the characteristics of the magnetospheres around the planets Jupiter and Saturn. Solar wind characteristics near these planets were deduced from those near the Earth using standard hydrodynamic equations. Planetary magnetic fields were estimated from nonthermal rf emissions, which were assumed to be synchrotron radiation. (Nonthermal radiation from Saturn has not been confirmed, so only a possible upper limit was used for that planet.) Based upon energy density relationships, the calculated standoff distances are ^40/?j and <50/?s for Jupiter and Saturn, respectively. The corresponding calculated magnetospheric tail lengths are ^0.5 a.u. and <0.7 a.u. Jupiter's Van Alien belts are ^ an order of magnitude more intense than the Earth's, while Saturn's are < an order of magnitude less than the Earth's. Centrifugal flattening does not appear to be a major effect for either planet's belts.