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Saturn's satellites reveal their secrets

点击量:   时间:2017-11-12 03:01:04

By Govert Schilling Iapetus His dark materials SATURN’S mottled moon Iapetus can blame the sun for its blemished complexion and split personality. Iapetus is a yin-yang satellite, with a black belly and a bright back. The two sides of its character were already evident to 17th-century astronomers, but not the source – which has been a mystery ever since. Now new clues come from images showing that the dark spots appear mainly on the sunward-facing slopes of craters and mountains. This suggests that they are the sun’s handiwork,