Io writes its history in hot metal

摘要

The flow of data from the Galileo spacecraft continues to challenge our thinking about Jupiter's satellites. The latest news comes from Io: infrared data analysed by McEwen et al. in Science show that the lava flows on Io are far hotter than all previous estimates, whether taken from the earlier Voyager missions, contemporary telescopic observations or earlier Galileo measurements. Temperatures in the range 1,700 to 2,000 K or more are inferred, similar to those of the primitive, magnesium-rich komatiite magmas that came from partial melting of the mantle during Earth's early history. These hot magmas tell us something about Io's structure, and its history.