In Mercury Images, Remarkable Features in a Crater

NASA’s messenger spacecraft sent back 1,200 pictures of Mercury from last October. These pictures reveal 30% of Mercury’s surface that has never been seen close up before. Included in these pictures is a view of the second-largest crater on Mercury. They call this the Rembrandt basin and scientists claim that the terrain inside Rembrandt is pristine from the time of the impact about 3.9 billion years ago. Usually, these are covered by volcanic flows. However, Rembrandt’s terrain has formed into ridges and troughs and is unlike any other impact basin seen before in the solar system.




http://www.nytimes.com/2009/05/05/science/space/05merc.html?ref=science