India Goes Big On Next-Generation Radio Astronomy With Elevated Engagement In ‘Square Kilometre Array’ Project

India will pool in Rs 1,250 crore and turn full member of an international effort to build the world’s largest and most sensitive radio telescope. The funding will support the telescope’s construction phase over the next seven years.

The mega astronomy project, called Square Kilometre Array (SKA), is one of the largest science projects in history, spanning collaboration across 16 countries, including long-time contributor India, from five continents and both the hemispheres. (More on India’s contribution later.)

It will lead to the building of two of the world’s largest radio telescope arrays in Australia and South Africa, covering an area of one million square metres — or a square kilometre, from where the project gets its name — to probe the universe in unprecedented detail.

Unlike the typical radio telescope with a large dish, as in the case of the historic Arecibo telescope in Puerto Rico, the SKA setup will see thousands of radio telescopes deployed in three unique configurations, enabling astronomers to survey the entire sky thousands of times faster than any system in use currently.

After it’s ready, the telescope’s image resolution quality will exceed that of the legendary Hubble Space Telescope by a factor of 50 times! What’s more, with all its might, the radio eyes will operate for 50 years or more.

It’s safe to say that, in combination with other large telescopes on the ground or in space, operational or under development, the SKA telescope will have a profound impact on scientific discovery.

For this reason, India’s funding approval and move to become full member on the project has stoked excitement within the Indian astronomy community.

"An important step for radio astronomy, and astronomy in general, in india," Professor K VijayRaghavan, a former principal scientific adviser to the Government of India, posted on X.

“This is a major step forward for astronomy in India: it will allow us to contribute technologically at the highest level, and benefit scientifically from use of the most sensitive facility,” Professor Yashwant Gupta, director of the National Centre for Radio Astrophysics (NCRA) of the Tata Institute of Fundamental Research (TIFR), said in an X post.

NCRA-TIFR and Professor Gupta have been leading India’s participation in the project for over a decade. More than 20 academic and research institutes in the country are engaged currently in the work.

Telescope’s Two Homes

The Karoo region in South Africa and the Murchison Shire in Western Australia are the two locations picked to host the giant telescope arrays.

The chief considerations for the site selection were the characteristics of the atmosphere above the sites, their ‘radio quietness’ — so that radio interference is of little worry — and a delicate balance between remoteness and accessibility.

While South Africa will host “SKA-Mid,” an array of 197 parabolic 15-metre-dish antennas, the traditional lands of the Wajarri Yamaji in Western Australia will host “SKA-Low,” an array of 131,072 smaller tree-like antennas.

The arrays in both continents will be built in such a way that they cover a vast area — the most distant antennas in the South African and Australian arrays will be 150 kilometres (km) and 65 km apart, respectively.

The collecting area for SKA-Mid will be 33,000 m², and for SKA-Low, will be 400,000 m². Further, the operating frequency will be about 50-350 MHz for SKA-Low and 350 MHz to 13.8 GHz for SKA-Mid.

Despite operating in different continents, both SKA-Mid and SKA-Low arrays will effectively act as one large telescope through the principle of interferometry. Working in unison, they will surpass the capabilities of existing similar instruments significantly.

Compared to the LOFAR telescope in the Netherlands, for instance, SKA-Low will offer 25 per cent better resolution, eight times the sensitivity, and the capability to survey the sky at a pace 135 times faster.

Similarly, SKA-Mid will feature four times the resolution, five times the sensitivity, and the ability to survey the sky at a pace 60 times faster in comparison to the Karl G Jansky Very Large Array (VLA) telescope in the United States (US).

Thanks to their power and sensitivity, the expectation is that the SKA telescopes will unveil the secrets of cosmic evolution, including the formation and development of the earliest stars and galaxies following the Big Bang, the influence of cosmic magnetism, the nature of gravity, and possibly life beyond Earth.

India’s Engagement With SKA

India has been involved in the SKA project since its inception in the 1990s, chiefly through the astronomy institute NCRA-TIFR.

With the NCRA becoming a member of the SKAO’s precursor organisation in 2014, India became a member in the SKA organisation a year later.

India has contributed as a technical partner over the years and even contributed to the creation of the intergovernmental organisation SKAO in early 2021. The SKAO is responsible for constructing, operating, and maintaining the SKA telescopes.

In February 2022, India signed a cooperation agreement with SKAO for continued participation in the various project activities, including engagement of the Indian industry in the technical work, while taking its time to deliberate further on membership and ratification of the SKAO Convention.

Now, in 2024, India is moving ahead with full membership, funding, and signing of the founding treaty.

India’s representation in the SKA organisation is strong, spreading out across the Council — the main governing body of the SKAO — as well as the Finance and Science & Engineering Advisory Committees.

Indian scientists also feature actively on 12 science working groups and hold co-chair positions in the solar, heliospheric, and ionospheric physics, epoch of reionisation, and pulsars groups.

India’s main representative, the NCRA is a proven radio astronomy champion, having built and operated the Giant Metrewave Radio Telescope in Pune.

For SKA, the TIFR institute played the leading role in successfully delivering the Telescope Manager element during the project’s critical design phase. It led an international consortium of nine institutions through the 2010s with the goal of designing software that would control, monitor, and operate the SKA telescopes.

India is primarily supplying its software muscle to the grand project. It is supervising the development of software that will be used to monitor and control the SKA telescopes. “This software will issue all the commands necessary to execute astronomical observations – akin to the human body’s neural system,” the SKAO website says.

The project will count on Indian software engineers to help manage the overall development of SKA software. This includes the Indian industry, whose participation is expected to help build capacity within the country and provide engineers with valuable exposure to large science projects.

Tata Consultancy Services and Persistent Systems, for example, have been working on the SKA project alongside NCRA scientists for years.

“We have leveraged the strength of India’s software industry to work in a spirit of collaboration with us, and to build a partnership which is well placed to make significant contributions to the construction of the management and control software of the SKA,” Professor Gupta of the NCRA was quoted as saying in a SKA document.

In the future, a SKA regional centre might come up in India to facilitate the processing, storage, and delivery of SKAO data products to the astronomy community.

As of 2020, about 150 scientists, including faculty members, postdoctoral fellows, and PhD students, from over 30 institutions were involved in SKA-related science areas. This community is expected to grow to about 250-300 by the time the first of the SKA telescopes is commissioned.

India’s Mega Science Synergies

India’s two other mega science projects under development, namely the Laser Interferometer Gravitational-Wave Observatory–India (LIGO India) and the Thirty Meter Telescope (TMT), will combine well with the SKA.

“Synergies between LIGO-India and SKA will involve detecting the gravitational waves using two different complementary techniques,” a 2020 summary of the SKA-India science case said.

LIGO India is a planned advanced gravitational-wave observatory that will operate from Indian soil as part of the worldwide network, which currently consists of two interferometres operating in the US — in Hanford, Washington, and Livingston, Louisiana.

LIGO’s fundamental currency is gravitational waves, which are a core prediction of Albert Einstein’s Theory of General Relativity. The LIGO network’s job is to catch these gravitational waves. LIGO India, when ready, will join in on this cosmic adventure.

The SKA India science case document says: “While LIGO-India will detect the signal arising from mergers of stellar remnants (e.g., neutron stars, black holes), the SKA will enhance our understanding by using the Pulsar Timing Arrays to detect mergers of supermassive black holes.”

The SKA’s tremendous radio vision will be turned upon celestial sources caught by ground-based detectors like LIGO-India to uncover the corresponding electromagnetic information.

Similarly, the TMT, another mega science project in which India is involved, and the SKA “will have lots of commonalities in science cases, starting from nearby star-forming galaxies to distant galaxies and accreting black holes,” according to the document.

The TMT will be the world’s most advanced and capable ground-based optical, near-infrared, and mid-infrared observatory. The 30-metre-diameter telescope will be built at Mauna Kea, Hawaii, US. India is a partner on the TMT project alongside CalTech, the University of California, and institutes in Canada, Japan, China and India.