On the night of Saturday, July 10, 2010, ESA’s Rosetta spacecraft passed by the 80-plus-mile-wide asteroid Lutetia at a distance of less than 2000 miles, and retured a series of wonderfully detailed images of this intriguing little member of our solar system. The image above, cropped and rotated 90º, shows Lutetia’s cratered surface, covered with grooves and strewn with boulders.

Asteroids are particularly interesting to astronomers because they are, in many cases, time capsules left over from the early formation of the solar system. Mineral-rich worlds that never coalesced enough to form another planet, they are now isolated islands in time, circling the sun in the vast distances between the orbits of Mars and Jupiter. Researchers will pore through the data returned by Rosetta this weekend and try to learn more about the composition of Lutetia, and whether it contains large amounts of metals – like iron – or is instead made of primitive carbon compounds. Either way, we will gain that much more insight into the fascinating family of worlds that share our journey through the universe.

Image credit: ESA 2010 MPS for OSIRIS Team MPS/UPD/LAM/IAA/RSSD/INTA/UPM/DASP/IDA

PS: Be sure to check out this very cool image taken by the narrow-angle camera showing Lutetia with Saturn visible in the background!

The International Rosetta Mission was approved in November 1993 by ESA’s Science Programme Committee as the Planetary Cornerstone Mission in ESA’s long-term space science programme. The mission goal was initially set for a rendezvous with comet 46 P/Wirtanen. After postponement of the initial launch a new target was set: Comet 67 P/Churyumov- Gerasimenko. On its 10 year journey to the comet, the spacecraft will pass by two asteroids: 2867 Steins (in 2008) and 21 Lutetia (in 2010).