Europe’s comet-bound Rosetta spacecraft did a little

sight-seeing over the weekend, snapping pictures of an asteroid known as

Lutetia, located in the Main Asteroid Belt between Mars and Jupiter.

Not much is known about Lutetia, which was first observed in

1852. One of the biggest mysteries about the asteroid is whether it is an old

carbon-laced rock left over from the creation of the solar system, or whether

its surface has metals, an indicator that it is part of a group of asteroids

believed to be fragments of the cores of much larger objects.

SLIDE SHOW: See more photographs snapped by Rosetta during Saturday’s flyby of asteroid Lutetia.

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Analysis of about 400 images and other data collected during

Rosetta’s 9-mile-per-second swoop by Lutetia on Saturday will fill in some of

the blanks. First impressions: Lutetia is very irregular in shape, with a face

severely pocked by wide impact craters and grooves. Its longest side is about

81 miles in length (130 kilometers.)

“I think this is a very old object,” Rosetta scientist

Holger Sierks, with the Max Planck Institute in Germany, said in a statement.

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Rosetta’s full suite of sensors, including cameras,

spectrometers and magnetic-field detectors, collected data during the approach

and flyby of Lutetia. The information is being radioed back to Earth for

analysis. Scientists hope to learn if the asteroid has any detectable

atmosphere and magnetic effects, as well as what its surface is made of and how

dense its body is.

Lutetia is the second asteroid Rosetta has visited en route

to comet 67P/Churyumov-Gerasimenko, an encounter that is scheduled to occur in

2014. The spacecraft flew past asteroid Steins in 2008.

Image: Asteroid Lutetia, in its first close-up. Credit: ESA