Arecibo - The Largest Telescope Ever Constructed

The Arecibo Observatory operates the largest telescope ever constructed, using a 305m dish constructed inside the depression left by a karst sinkhole.

The telescope is located about 9 miles (14 km) south-southwest from the town of Arecibo in Puerto Rico, although the observatory belongs to the United States and is operated by Cornell University under cooperative agreement with the National Science Foundation.

The dish is the largest curved focusing dish on Earth, giving Arecibo the largest electromagnetic-wave gathering capacity. The receiver is located on a 900-ton platform which is suspended 150m in the air above the dish by 18 cables running from three reinforced concrete towers.



The platform has a 93 m long rotating bow-shaped track on which receiving antennas are mounted, this allows the telescope to observe any region of the sky. Puerto Rico's location near the equator allows Arecibo to view all of the planets in the solar system.

Construction began in the summer of 1960, it started operating on November 1, 1963. Only a few months later, on April 7, 1964, it was used it to correctly determine the rotation rate of Mercury. In 1968 it confirmed the existence of neutron stars, in 1974 it discovered the first binary pulsar. In 1982, the first millisecond pulsar (spining 642 times per second) was detected by the Arecibo telescope, followed by the first directly imaged asteroid in 1989.

The following year a pulsar with three orbiting planets was detected - these were the first extra-solar planets ever discovered. In 1994 the distribution of ice in the poles of Mercury was mapped and in January 2008 prebiotic molecules were reported after radio spectroscopy measurements of a distant starburst galaxy.

Arecibo is also the source of data for the SETI@home distributed computing project and was used for the SETI Institute's Project Phoenix observations. In 1974, the Arecibo message, an attempt to communicate with extraterrestrial life, was transmitted from the radio telescope.

The Arecibo telescope could also be seen in the James Bond movie "Golden Eye" and in the film "Contact".

Sumber : galaxiki.org