Made by Ball Aerospace, the 18 beryllium mirror segments for the James Webb Space Telescope are ready to be delivered to NASA.
That may sound ambitious, especially since only about 10,000 such asteroids have been catalogued to date.
The private space telescope forms the heart of Project Sentinel, a deep-space mission being unveiled today in Mountain View, Calif., by a nonprofit group of scientists and explorers that advocates better space rock monitoring.
Comet Hartley 2 will get its portrait taken on Thursday by NASA's EPOXI spacecraft. NASA will snap 6,000 high-resolution images of 103P/Hartley 2, a small comet that hangs out around Jupiter's orbit.