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Paper: New Views of Diverse Worlds
Volume: 457, Connecting People to Science
Page: 17
Authors: Blewett, D.
Abstract: Spacecraft exploration is in the process of revolutionizing our knowledge of the airless rocky bodies in the inner Solar System. Mercury has long been viewed as a planetary “end-member”, but NASA's MESSENGER spacecraft, which flew past the innermost planet three times in 2008–09 and entered orbit in March of 2011, is finding that Mercury is even stranger than we thought. Mercury is weird in essentially all its characteristics: interior structure, surface composition, geology, topography, magnetic field, exosphere, and interaction with the space environment. Closer to home, a flotilla of international probes have targeted the Moon in the past few years. Giving lie to the “been there, done that” attitude held by many toward the Moon, the new missions are making many new discoveries and reminding us that there is much we don't know about our nearest planetary neighbor, and that rich opportunities for exploration are waiting nearby. Finally, I'll present findings from NASA's Dawn spacecraft, which will begin its orbital mission around the asteroid Vesta in mid-July 2011. Vesta is sometimes called “the smallest terrestrial planet” because it has separated into a crust, mantle, and core, and experienced a protracted geological evolution. Vesta is probably the source of a common class of meteorites, so we have abundant samples that help to inform our interpretation of the data to be obtained by Dawn. Mercury, the Moon, and Vesta are worlds who share some characteristics, but have taken radically different evolutionary paths. They provide insight into the most fundamental geological processes that likely affect all rocky planets—around our Sun or beyond.
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