Arecibo Observatory in Puerto Rico, is the location of the world's largest single-dish radio telescope. Because radio telescopes can work at all times of day and in all kinds of weather, the observatory operates 24 hours a day. It celebrated its 50th anniversary of work in 2013.

While the observatory does a lot of astronomy work, it is perhaps most famous for being the site of the huge Search for Extra Terrestrial Intelligence (SETI) message directed at the globular cluster M13 in 1974. Besides its scientific work, Arecibo is known for being the location of a climactic fight in "Goldeneye," a 1995 James Bond film starring Pierce Brosnan.

These days Arecibo is frequently used for finding asteroids that are swinging close to Earth. The observatory focuses on those that could pose a danger to the planet, making an effort to accurately measure their sizes to gauge the potential impact it could have.

In 2013 for example, the observatory watched the arrival of asteroid 2012 DA14 which passed within 17,200 miles (27,000 kilometers) of Earth. It was a close flyby, but NASA emphasized the asteroid passed by at a safe distance.

Besides asteroid research, Arecibo is also the site of the Planetary Habitability Laboratory at the University of Puerto Rico at Arecibo. The group has a habitable planets catalog that tracks the number of alien worlds in other solar systems that could be in the Goldilocks zone (an area that is not too hot or cold for life), of their respective stars.

More Info: www.space.com