Cornell University had established Arecibo Observatory in Puerto Rico six years before the first man set his foot on moon, and since its establishment, the observatory has played a significant role in observing the planets without moving its 1000 foot-wide reflector. It was with this telescope that researchers computed the speed of Mercury and Venus rotations, and observed the surface features of moon and other planets neighboring Earth. Also, this is the same telescope that led to the discovery of first planetary system revolving around the sun.


Presently, it still lists as one of world's largest radio telescopes and is accessible to scientists 24/7. The Arecibo Observatory celebrates it's 50th anniversary today, 1st November 2013.