The asteroid P/2010 A2, imaged by OSIRIS on Rosetta

A view of the asteroid P/2010 A2, imaged by the OSIRIS Narrow Angle Camera on the ESA spacecraft Rosetta. The asteroid underwent a high-speed collision with a small rock, producing a trail of dust. On the left is the full field of view of the camera, covering 2.2 degrees on a side, which shows the crowded star field and nebula (in the constellation Taurus, the Bull) that the asteroid passed in front of in March 2010. On the right is a close-up of the asteroid. The close-up combines 16 separate images taking almost 4 hours of integration, and is 200 arcseconds on a side (approximately 140 000 km at the distance of the asteroid). The stellar background had to be carefully subtracted from each individual image before they were combined to reveal the faint dust trail.