The past fifty years represent a golden age for astronomy. Exciting new discoveries occurred across a wide range of phenomena. Our intellectual horizons expanded correspondingly. At the edge of that expansion, often creating mighty explosions of his own, one invariably finds Peter Goldreich.
Goldreich’s career began auspiciously with his explanation, with Peale, of the role of resonances in the solar system. This understanding formed the basis for the later successful prediction that volcanoes would exist on Io. When the motion of Io was found to correlate with intense decametric radio emission from Jupiter, Goldreich and Lynden-Bell put forth an elegant explanation that relied on the presence of a million-ampere tube of electric current flowing between Io and Jupiter’s magnetosphere, a prediction that was later confirmed by direct satellite imaging of the hot spot in Jupiter’s atmosphere that is linked magnetically to Io.