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Friday, November 21, 2008

Photo: Hell on Earth? Scientists Debate Planet's Early Years


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A zircon—the small pink crystal—is seen in this microscope image taken with polarized light. The zircon, about 150 micrometers long (a micrometer is thousandth of a millimeter), was collected by a submersible at the Hess Deep in the equatorial Pacific Ocean.

Zircons are at the center of a debate over the temperature of early Earth. New evidence suggests that instead of cooling rapidly after its birth, Earth stayed hot and hellish.

Image courtesy Laurence Coogan