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.
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.
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