The results from the Messenger spacecraft’s third and final flyby of Mercury are finally in and cover ground never before mapped. But they leave scientists wanting more.
NASA’s orbiter swung around Mercury on Sept. 29, 2009 to get a gravitational boost before settling into orbit in March 2011. The snapshots it took as it flew past provide tantalizing glimpses of young volcanic vents, violent magnetic storms and mysterious concentrations of calcium in the atmosphere. But the view was cut short by the spacecraft going into safe mode just before its closest approach.
Planetary scientists are now anxious for the main event.
“It will be so great when we go into orbit,” said planetary scientist Brett Denevi of Arizona State University, co-author of a new paper describing the new view of Mercury’s surface. “This is all just a teeny snapshot. Going into orbit will be like two flybys every day.”
Three papers published online July 15 in Science Express describe what Messenger saw on its last flyby. Scientists have now mapped 98 percent of the planet by combining the new observations with the first two flybys in January and October 2008, plus the Mariner 10 mission in the ’70s, Denevi said. The latest flyby filled in a 360-mile-wide gap that had never been imaged before.
