WHY IT MATTERS: S.C. Solomon at Carnegie Institution of Washington says the new insights will help scientists link Mercury's surface evolution to its interior history and to compare the planet with the geologic histories of the Earth, Venus, the Moon, and Mars.
NASA/Johns Hopkins University/Carnegie This kidney-shaped volcanic vent on Mercury is evidence that the planet's surface was formed by volcanic activity early in the planet's history.
Relatively little is known about Mercury, the innermost of the four terrestrial planets in our solar system. In 1975 the Mariner 10 spacecraft returned intriguing images that showed smooth plains covering large swaths of Mercury's surface. But scientists could not determine whether the plains had been created by volcanic activity or by material ejected from below the surface when objects had collided into it. Thus, they could not reach a consensus over Mercury's geologic past. The new MESSENGER space mission has found evidence of past volcanic activity.
Source:
Audio excerpt from the weekly podcast of the journal Science
