The MESSENGER spacecraft did the first of its three flybys of Mercury on January 14 before going into orbit around the planet in 2011. Only one spacecraft had visited Mercury and that was in the 1970s. That one only saw one side of the planet. Now we can see more of the planet, including the complete Caloris basin that the previous spacecraft, Mariner 10, only saw part of. Now we know of those strange black craters on the rest of Caloris basin. When MESSENGER goes in orbit, it will do measurement of the composition of the surface so we'll find out what those black craters are made of. More cliffs in the surface was found in the newly imaged areas.
Mission homepage
More pictures
Approach
First look at the previously unseen side Caloris basin is the big light circle in the upper right
Cliff
Mission homepage
More pictures
Approach
First look at the previously unseen side Caloris basin is the big light circle in the upper right
Cliff
