On July 10, the European Space Agency's Rosetta spacecraft cruised past asteroid Lutetia, coming within 3,160 kilometers (1,950 miles) at a velocity of 15 kilometers (9 miles) per second, completing the flyby in just a minute. The craft will rendezvous with comet 67P/Churyumov-Gerasimenko in 2014. Michigan Engineering alum Claudia Alexander (AOSS PhD '93), project scientist for the U.S. role in the Rosetta mission, said that NASA instruments aboard Rosetta should unravel at least a little of the mystery that enshrouds Lutetia, the biggest asteroid visited by a spacecraft.
Before the flyby, scientists knew little more than the asteroid's size (a width of 62 miles). But Rosetta's cameras and other instruments took the first close-up image of the object, collected data to derive its mass and reveal surface properties, record the solar wind nearby and look for evidence of an atmosphere.
Read more about the Rosetta mission at http://rosetta.jpl.nasa.gov.