![]() |
Steins: A diamond in the sky
The first images from Rosetta’s OSIRIS imaging system and VIRTIS infrared spectrometer were derived from raw data this morning and have delivered spectacular results. "Steins looks like a diamond in the sky," said Uwe Keller, Principal Investigator for the OSIRIS imaging system from the Max Planck Institut Fuer Sonnensystemforschung, Lindau. Visible in the image are several small craters on the asteroid, and two huge ones, one of which is 2 km in diameter, indicating that the asteroid must be very old. The images are 50 to 60 pixels in diameter, enough to characterise the shape and other characteristics of the body of the asteroid.
The chain is composed of about 7 craters. To determine the age of the asteroid, a count of the craters on the asteroid’s surface has been started (the more the number of craters, the older the asteroid). So far, 23 craters have been spotted. From the images, scientists will try and understand why the asteroid is unusually bright, and how fine grains of the surface regolith are. This will tell them more about how the asteroid formed.
The OSIRIS imaging system's Wide Angle Camera (WAC) worked perfectly through the fly-by. The OSIRIS team expects that the images that they will retrieve from the Narrow Angle Camera (NAC) will be of comparable resolution. This will add to the detailed colour information and hence to knowledge of the surface composition.
After analysis of the Rosetta data, Steins will be one of the best-characterised asteroids so far.
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||