Rosetta Approaches Asteroid Lutitea . ... In 2010, ESA's robotic Rosetta spacecraft zipped past the asteroid 21 Lutetia taking data and snapping images in an effort to better determine the history of the asteroid and the origin of its unusual colors . ... The 100-kilometer across Lutetian is currently the largest asteroid or comet nucleus that has been visited by a human-launched spacecraft. ... NASA Web Site Statements, Warnings, and Disclaimers . NASA Official: Jay Norris. ...