An observatory with a number of telescopes, used primarily for solar research. NASA has built a three-meter mirror telescope using a mirror composed of liquid mercury, continuously rotated to form a nearly flawless reflector. This instrument is used to track space debris composed of fragments of man-made junk orbiting the earth, which is dangerous to satellites' manned missions. The device can detect a piece as small as half an inch in diameter, which, even at this size, would blast through any space borne object it came in contact with.
Sunspot National Solar Observatory, New Mexico