Craft may help explain widespread volcanism on closest planet to the sun
NASA’s MESSENGER spacecraft has become the first probe ever to enter orbit around Mercury.
Having settled the craft into a path around the sun’s nearest neighbor on March 17, mission scientists plan to switch on the robotic craft’s suite of seven instruments March 24, and the first observations from orbit will be beamed to Earth on April 4.
To shield the craft from the planet’s highest temperatures, MESSENGER (short for Mercury Surface, Space Environment, Geochemistry and Ranging) takes a highly elliptical path about Mercury, swooping as close as 200 kilometers from the surface and then venturing more than 15,000 kilometers away every 12 hours.
MESSENGER had already visited the planet during three flybys in 2008 and 2009. During those passes, MESSENGER found evidence that Mercury’s surface has been sculpted by widespread volcanism (SN On