28 October 2011
Vol 334, Issue 6055

About The Cover

Cover image expansion

COVER Asteroid 21 Lutetia, as seen by the Rosetta spacecraft from a distance of ~3500 kilometers in July 2010. Lutetia, 120 kilometers across, is a remnant planetesimal from the time of our solar system's formation and is one of the largest asteroids that have been visited by a spacecraft. A series of three Reports beginning on p. 487 describe Rosetta's observations of Lutetia's surface, density, and composition. Image: ESA 2011 MPS for OSIRIS Team MPS/UPD/LAM/IAA/RSSD/INTA/UPM/DASP/IDA.