(PhysOrg.com) -- A NASA spacecraft will conduct the second of
three flybys of Mercury on Oct. 6 to photograph most of its
remaining unseen surface and collect science data. The MErcury
Surface, Space ENvironment, GEochemistry, and Ranging, or
MESSENGER, spacecraft will pass 125 miles above the planet's
cratered surface, taking more than 1200 pictures. The flyby also
will provide a critical gravity assist needed for the probe to
become, in March 2011, the first spacecraft to orbit Mercury.
"The results from MESSENGER's first flyby of Mercury resolved
debates that are more than 30 years old," said Sean C. Solomon,
the mission's principal investigator from the Carnegie
Institution of Washington. "This second encounter will uncover
even more information about the planet." During the spacecraft's
first flyby on Jan. 14, its cameras returned images of
approximately 20 percent of Mercury's surface never before seen
by space probes. Images showed that volcanic eruptions produced
many of Mercury's plains, its magnetic