spacetoday.net: MESSENGER reveals volcanic activity, magnetic storms at Mercury

Posted: Fri, Jul 16, 2010, 7:02 AM ET (1102 GMT)
MESSENGER illustration (JHUAPL)

Observations by NASA's MESSENGER spacecraft have provided new insights into Mercury's volcanic history and its magnetic storms. PApers published in the journal Science Express summarize data collected by the spacecraft during its third flyby of Mercury last September. Those observations include images of a basin, named Rachmaninoff, with a smooth, sparsely cratered surface, evidence that the basin is relatively young. Scientists said this indicates that the planet's period of volcanic activity may have lasted longer than earlier thought, extending into the second half of the solar system's history. MESSENGER also observed the buildup of energy in substorms in the planet's magnetic tail, with 10 times the increase in energy and at 50 times the speed of similar events in the Earth's magnetic field. MESSENGER, launched in 2004, is scheduled to enter orbit around Mercury next year