World's Largest Radio Telescope

Date: 1963
Owner: National Astronomy and Ionosphere Center
Source Type: Images


This radio telescope near Arecibo, Puerto Rico, is the largest telescope in the world. Radio telescopes work best in isolated valleys where there are few extraneous waves to interfere with the data they collect. This dish, measuring 450 feet from top to bottom and covering 18.5 acres of land, is built inside the mouth of a dead volcano. It has undergone two significant technological updates (in 1973 and 1997) and is currently the world's most powerful dish. Since the 1997 modifications, the dish has been used to study galactic gasses, asteroids, and space dust like that found in Saturn's rings.

The Arecibo dish, completed in 1963, is a prime example of the big science that came to dominate astronomy in the decades after World War II. To design the necessary technologies and fund the $9 million dish, the project was a massive collaboration amongst some of the largest and most well funded scientific and government institutions in the U.S., including the Advanced Research Projects Agency of the Defense Department, Air Force Cambridge Research Laboratories, Cornell University, and the Army Corps of Engineers. The astronomy practiced at this facility was a far cry from that of the early twentieth century, an era when individual observers staring into optical telescopes still made most discoveries in the heavens. Arecibo and other modern telescopes required computers and other equipment (designed by specialists and not the astronomers themselves) that created a much larger distance between space and scientist.

This dish also draws attention to the colonial relationship between the U.S. and Puerto Rico. Much like the Spanish transformed the Caribbean's landscape (and society) by converting it into space for plantation agriculture, the U.S. dish also changed Puerto Rico's land to further its own imperial goals. Of course, a radio telescope to study the ionosphere (the dish's original purpose) is hardly as exploitative as slave-grown sugar, but the process of imposing foreign science onto the landscape of a lesser power is just the same.

Reference: "Largest Radio-Radar Telescope Unveiled." In The Science News-Letter, vol. 84, no. 21 (Nov. 23, 1963), pp. 323.

CITATION: View of Arecibo Observatory. Image courtesy of the NAIC — Arecibo Observatory, a facility of the NSF.