Online Courses (English)
This just in:

State PCS

Daily Updates

Important Facts For Prelims

SARAS 3 Telescope

  • 10 Mar 2022
  • 4 min read

Why in News

Recently, the Indian researchers at RRI (Raman Research Institute) in a study using the SARAS 3 radio telescope, have conclusively denied a recent claim of the discovery of a radio wave signal from cosmic dawn.

  • In 2018 a team of researchers from Arizona State University (ASU) and MIT in the US detected a signal from stars emerging in the early universe using data from the EDGES radio telescope.
  • The Cosmic Dawn is the period from about 50 million years to one billion years after the Big Bang when the first stars, black holes, and galaxies in the Universe formed.
  • The 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.

What are Radio Waves and Radio Telescopes?

  • Radio waves have the longest wavelengths in the electromagnetic spectrum. They range from the length of a football to larger than our planet. Heinrich Hertz proved the existence of radio waves in the late 1880s.
  • Radio telescopes collect weak radio light waves, bring it to a focus, amplify it and make it available for analysis.
  • They help study naturally occurring radio light from stars, galaxies, black holes, and other astronomical objects.
  • These specially-designed telescopes observe the longest wavelengths of light, ranging from 1 millimetre to over 10 metres long. For comparison, visible light waves are only a few hundred nanometers long, and a nanometer is only 1/10,000th the thickness of a piece of paper! In fact, we don’t usually refer to radio light by its wavelength, but by its frequency.

What is SARAS-3 Radio Telescope?

  • SARAS is a niche high-risk high-gain experimental effort of RRI.
  • SARAS aims to design, build and deploy in India a precision radio telescope to detect extremely faint radio wave signals from the depths of time, from our “Cosmic Dawn” when the first stars and galaxies formed in the early Universe.

What are the Findings?

  • SARAS 3 did not find any evidence of the signal claimed by the EDGES experiment.
  • The presence of the signal is decisively rejected after a careful assessment of the measurement uncertainties.
  • The detection reported by EDGES was likely contamination of their measurement and not a signal from the depths of space and time.
  • However, astronomers still do not know what the actual signal looks like.


Consider the following phenomena: (2018)

  1. Light is affected by gravity.
  2. The Universe is constantly expanding.
  3. Matter warps its surrounding space-time.

Which of the above is/are the prediction/predictions of Albert Einstein’s General Theory of Relativity, often discussed in media?

(a) 1 and 2 only
(b) 3 only
(c) 1 and 3 only
(d) 1, 2 and 3

Ans: (d)

Source: PIB

SMS Alerts
Share Page