Mercury is full of volcanoes and other surprises, reveals initial data from NASA’s MESSENGER spacecraft—the first to conduct an in-depth investigation of the solar system’s smallest planet in more than 30 years. … In January MESSENGER made its first of three flybys planned before 2011, when the spacecraft settles into orbit around the enigmatic planet.
During the pass, MESSENGER snapped more than 1,200 images of Mercury‘s scorched sunlit side, including 21 percent of the surface Mariner 10 never saw.
The images reveal a dynamic surface pockmarked by craters and volcanoes. They also shed more light on Mercury’s magnetic field, which mirrors Earth’s on a tiny scale.
And they reveal widespread slip faults, relics of a time when the planet’s already-frozen surface weathered a spectacular collapse atop a shrinking, cooling core. – natgeo