At 12:31 A.M. EDT October 6, NASA’s MESSENGER spacecraft will skim within 125 miles (200 kilometers) of Mercury’s surface. MESSENGER — short for MErcury Surface, Space ENvironment, GEochemistry, and Ranging — has flown past Mercury once already this year. On January 14, the craft came equally close to the innermost planet, imaging Mercury’s cratered surface and studying its puzzling magnetic field and thin atmosphere.
Yet on October 6, the Sun will be illuminating the hemisphere that lay in darkness back in January. “MESSENGER will view parts of Mercury no one has ever seen up-close before,” says Astronomy magazine Senior Editor Richard Talcott. Not only will the probe observe the opposite half from what it did last time, but it also will reveal some 30 percent of the planet’s surface missed by the Mariner 10 spacecraft in the mid-1970s. This represents the largest area of terra incognita remaining in the solar system.
“MESSENGER’s January flyby revealed unexpected features in the new areas it observed,” Talcott adds. “Now, expectations are running high that more bizarre terrain may show up.”
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MESSENGER made its second flyby of the innermost planet October 6, and it’s already sending back stunning images of never-before-photographed features. Image gallery
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During flyby, one instrument will look at reflected light from Mercury’s surface to better determine the mineral composition of the planet.
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Data from MESSENGER’s first flyby of the planet closest to the Sun have some scientists thinking unique surface structures formed from impacts, others suspect volcanic activity.
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Planetary scientists are starting to make sense out of the 500 megabytes of data returned by the MESSENGER spacecraft during its January 14 flyby of Mercury.
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MESSENGER’s recent flyby of Mercury has provided scientists with an entirely new, and surprising, view of the innermost planet.
MESSENGER at Mercury
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For the first time in more than 30 years, a spacecraft has returned to Mercury, providing images from sections of the planet that have never been viewed by a spacecraft.
“Setting our sights on Mercury,” Rich Talcott
Find out what MESSENGER discovered about the innermost planet so far.
MESSENGER at Mercury
Senior Editor Rich Talcott explains MESSENGER’s first flyby of Mercury.