Why in News?

• Scientists in India will now also be part of the international mega-science project, the Square Kilometer Array Observatory (SKAO), that will function as the world’s largest radio telescope.
• India’s Giant Metrewave Radio Telescope (GMRT) is amongst the world’s six large telescopes.

What’s in Today’s Article?

• About Radio Telescope (Definition, Utility, how it works)
• About GMRT (Details, Objectives, NCRA, etc.)
• About SKAO (History, Purpose, India’s Role, etc.)
• Gravitational Waves, LIGO 

What is a Radio Telescope?

• Radio telescopes detect and amplify radio waves from space, turning them into signals that astronomers use to enhance our understanding of the Universe.
• All astronomy is about observing waves of light.
• Stars, galaxies and gas clouds in space emit visible light as well as light from other parts of the electromagnetic spectrum in the form of radio waves, gamma rays, X-rays, and infrared radiation.
• In its simplest form a radio telescope has three basic components:
  • One or more antennas pointed to the sky, to collect the radio waves
  • A receiver and amplifier to boost the very weak radio signal to a measurable level, and
  • A recorder to keep a record of the signal.
• Radio telescopes can be used both night and day.

About Giant Metrewave Radio Telescope (GMRT):

• The Giant Metrewave Radio Telescope (GMRT), located near Narayangaon, Pune, is an array of 30 fully steerable parabolic radio telescopes of 45 metre diameter, observing at metre wavelengths.
• It is a low-frequency radio telescopethat helps investigate various radio astrophysical problems ranging from nearby solar systems to the edge of the observable universe.
• The telescope is operated by the National Centre of Radio Astrophysics (NCRA). It became operational in the year 2000.
  • NCRA is a part of the Tata Institute of Fundamental Research (TIFR), Mumbai.
• GMRT is one of the most challenging experimental programmes in basic sciences undertaken by Indian scientists and engineers.
• Astronomers from all over the world regularly use this telescope to observe many different astronomical objects such as the Sun, Jupiter, exoplanets, magnetically active stars, etc.
• In 2021, GMRT became only the third in India to be recognised with the Institute of Electrical and Electronics Engineers (IEEE) Milestone facility.

National Centre for Radio Astrophysics:

• The National Centre for Radio Astrophysics is a research institution in India in the field of radio astronomy.
• It is located in the Pune University Campus.
• The Centre has its roots in the Radio Astronomy Group of TIFR, set up in the early 1960s under the leadership of Prof. Govind Swarup.

Square Kilometer Array Observatory (SKAO):

• About
  • The Square Kilometer Array is an intergovernmental international radio telescope project being built in Australia and South Africa.
  • It is being built in the southern hemisphere as the view of the Milky Way galaxy is the best and radio interference at its least.
  • Some of the countries taking part in building the SKA include the UK, Australia, South Africa, Canada, China, France, India, Italy and Germany.
• Objective:
  • To build and operate cutting-edge radio telescopes to transform our understanding of the Universe, and deliver benefits to society through global collaboration and innovation.
• Construction
  • The project has two phases of construction: the current SKA1, commonly just called SKA, and a possible later significantly enlarged phase sometimes called SKA2.
  • The construction phase of the project began in December 2022 in both South Africa and Australia.
• Headquarters: Jodrell Bank Observatory, United Kingdom
• India’s Role:
  • India, through the NCRA and some other institutions, has been involved in the development of SKAO since its inception in the 1990s.
  • India’s main contribution to the SKA is in the development, and operation, of the Telescope Manager element, the “neural network” or the software that will make the telescope work.
    • NCRA led an international team from nine institutions and seven countries to develop the software.
  • Countries have to sign, and ratify, the SKAO convention to formally become members.
  • Recently, the Central Government decided to join the project, with a financial sanction of Rs 1,250 crore.

Gravitational Waves

• Gravitational waves are ‘ripples’ in space-time caused by some of the most violent and energetic processes in the Universe.
• Albert Einstein predicted the existence of gravitational waves in 1916 in his general theory of relativity.
• Einstein’s mathematics showed that massive accelerating objects (things like neutron stars or black holes orbiting each other) would disrupt space-time in such a way that ‘waves’ of undulating space-time would propagate in all directions away from the source.
• These cosmic ripples would travel at the speed of light, carrying with them information about their origins, as well as clues to the nature of gravity itself.

Laser Interferometer Gravitational-Wave Observatory (LIGO)

• It is the world’s largest gravitational wave observatory.
• LIGO consists of two widely-separated interferometers within the United States—one in Hanford, Washington and the other in Livingston, Louisiana—operated in unison to detect gravitational waves.