30 September 2011
Vol 333, Issue 6051

About The Cover

Cover image expansion

COVER Enhanced-color image of Mercury's surface showing a close-up of shallow, rimless depressions, or hollows (blue), inside the Raditladi impact basin (foreground ~12 kilometers across). These landforms were likely formed by the loss of volatile-containing material exposed by impacts and support the inference that Mercury's interior contains more volatile materials than predicted. Results from MESSENGER's orbital observations appear in a series of Reports beginning on p. 1847 Image: NASA/The Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington