International Space Agencies – Missions and Discoveries

Arecibo Radio Telescope


From UPSC perspective, the following things are important :

Prelims level : Arecibo Radio Telescope

Mains level : Not Much

A massive radio telescope at Puerto Rico’s Arecibo Observatory — one of the world’s largest — collapsed on after sustaining severe damage, following 57 years of astronomical discoveries.

Try this PYQ:

Which of the following is/are cited by the scientists as evidence/evidence for the continued expansion of the universe?

  1. Detection of microwaves in space
  2. Observation of redshirt phenomenon in space
  3. Movement of asteroids in space
  4. Occurrence of supernova explosions in space


(a) 1 and 2 only

(b) 2 only

(c) 1, 3 and 4

(d) None of the above can be cited as evidence.

Arecibo Telescope

  • The Arecibo Observatory, also known as the National Astronomy and Ionosphere Center (NAIC), was an observatory in Arecibo, Puerto Rico owned by the US National Science Foundation (NSF).
  • It was the world’s largest single-aperture telescope for 53 years, surpassed in July 2016 by the Five-hundred-meter Aperture Spherical Telescope (FAST) in China.
  • The second-largest single-dish radio telescope in the world, it had withstood many hurricanes and earthquakes since it was first built in 1963.

Its contributions

  • Being the most powerful radar, scientists employed Arecibo to observe planets, asteroids and the ionosphere.
  • It made several discoveries over the decades, including finding prebiotic molecules in distant galaxies, the first exoplanets, and the first millisecond pulsar.
  • In 1967, Arecibo was able to discover that the planet Mercury rotates in 59 days and not 88 days as had been originally thought.
  • In the following decades, it also served as a hub in the search for extraterrestrial life, and would look for radio signals from alien civilizations.
  • In 1993, scientists Russell Hulse and Joseph Taylor were awarded the Nobel Prize in Physics for their work on the observatory in monitoring a binary pulsar.
  • It provided a strict test of Einstein’s Theory of General Relativity and the first evidence for the existence of gravitational waves.
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