Return to Home Page
[...] There was a definite prediction that Jupiter will get a new dust ring, but much further out than the existing ring, in the vicinity of Io. It will come from dust particles that are braked and captured by the magnetosphere, but on the average it will take several orbits to do that. Thus the ring will take maybe 10 years to accumulate. The optical depth of the ring is extremely uncertain. Someone else said that Io would sweep up the material in about 50 years. Perhaps the most interesting presentation came from Jay Melosh of LPL and Paul Schenk of LPI, who showed images of several of a dozen or so crater chains identified on Ganymede and Callisto. They show an astonishing morphological similarity to what we see for Shoemaker-Levy, with very straight chains, the crater sizes obeying a gaussian size distribution (not a power law), the biggest craters in the middle of the chain, etc. Of course these chains are much more compact, and apparently were produced when a broken-up comet hit one of the satellites on its FIRST egress from the Roche lobe. Their numbers imply that Jupiter splits a 1-km comet once in 80 years on the average, in good agreement with Shoemaker's frequency estimate from entirely different considerations. Ben Zellner Space Telescope Science Institute
Return to the Daisaku Nogami
vsnet-adm@kusastro.kyoto-u.ac.jp
