#GS-03 Science and Technology

For Prelims


  • SARAS 3 is a radio telescope built by RRI (Raman Research Institute).
  • SARAS is a correlation spectrometer designed for precision measurements of the cosmic radio background and faint features in the sky spectrum at long wavelengths and operates in the octave band 87.5–175 MHz.
  • SARAS 3 is an indigenously invented and built radio telescope that can detect extremely faint radio wave signals from the depths of time.
  • It can detect faint cosmological signals, especially radiation emitted by hydrogen atoms at the 21-cm wavelength (1.4 GHz) arising from the depths of the cosmos.

Significance of SARAS 3

  • SARAS-3 is the first telescope worldwide to reach the required sensitivity and crossverify the claim of the signal detection.
  • The telescope was first deployed in rural Timbaktu Collective in Anantapur district.
  • The subsequent deployment took place in the wilderness of transHimalayan Ladakh.
  • Currently the telescope has been deployed over the Dandiganahalli Lake and Sharavati backwaters since 2020.
  • The idea of floating the radio telescope on a raft on water, had never been conceived of in the world.
  • This has allowed astronomers and researchers have been able to determine properties of radio luminous galaxies formed just 200 million years post the Big Bang, a period known as the Cosmic Dawn.
  • The results from the SARAS 3 telescope are the first time that radio observations of the averaged 21-centimetre line have been able to provide an insight into the properties of the earliest radio loud galaxies that are usually powered by supermassive black holes.
  • SARAS 3 had improved the understanding of astrophysics of Cosmic Dawn by telling astronomers that less than 3% of the gaseous matter within early galaxies was converted into stars.


  • RRI is an autonomous research institute engaged in research in basic sciences.
  • The institute was founded in 1948 by the Indian physicist and Nobel Laureate Sir C V Raman.