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