4 min readBengaluruSep 19, 2024 10:26 AM IST
First published on: Sep 19, 2024 at 09:43 AM IST
Square Kilometer Array (SKA), the world’s largest radio telescope in the making, has carried out its first observations, signalling that at least a part of the yet-to-be-completed facility has become functional.
SKA is a network of thousands of radio antennas, 197 of them located in South Africa and more than 1.3 lakh in Australia, designed to function as one single unit that will make it the world’s largest radio telescope.
The array in South Africa is named SKA-Mid while the one in Australia is called SKA-Low, the names reflecting the frequency ranges they operate in. The facility is meant to observe the universe in a new way, and probe questions related to the origins of the universe, formation and evolution of galaxies and seeking the origins of life.
A few days ago, astronomers and engineers working at the Australian facility integrated data from the two stations of the SKA-Low to obtain co-ordinated observational results, thus confirming its capabilities to function as an interferometer.
Interferometers are instruments that use the principle of wave interference to make scientific measurements. It is a technique that allows scientists to gather a variety of information — from determination of distance to detecting gravitational waves — by splitting and recombining light beams or other electromagnetic waves. SKA-Low and SKA-Mid would also work as interferometers.
The first results have come just about six months after the first antennas in the SKA-Low array were installed in western Australia.
The first results have come just about six months after the first antennas in the SKA-Low array were installed in western Australia.
The SKA is an international science project with headquarters in the United Kingdom. In December last year, India, which has been collaborating on the project since its inception, became a full member country in the international consortium building this telescope across two continents.
A total of 1,31,072 lakh antennas, each measuring two-metres in height, will collectively form the SKA-Low. The SKA-Mid will comprise 197 large parabolic dish antennas. Offering the largest bandwidth of observations, SKA-Low will operate from Australia in the frequency bandwidth 50 – 350 Mega Hertz while SKA-Mid is designated to operate in 350 MHz – 15.4 Gigahertz band in South Africa.
Each of SKA-Low’s proposed 512 stations will have 256 antennas, thus taking the total number of antennas to 1,31,072. Since the first antenna that was installed in March, the total installed antennas until August was 1,024 corresponding to four stations. The first image of the sky was obtained in early August. A similar first image was obtained in January this year from the prototype dish assembled for SKA-Mid in South Africa.
“The tests involve observing known radio sources or bright sources which are used to test the antenna’s basic working, its fidelity and is used for calibration purposes,” Yashwant Gupta, centre-director, National Centre for Radio Astrophysics (NCRA) told The Indian Express.
India’s current effort is focused around software development, that is, to integrate the appropriate software along with the antenna control structure required both for SKA-Mid and SKA-Low. During the past four months, the Indian science team has been involved in the process of data analysis.
By early next year, the Indian team, inclusive of industries, will also go on to develop and produce digital hardware for signal processing at each of the 256 stations at SKA-Low. Teams from India and Italy will primarily be involved in this task.
Several tools developed will be deployed and kept ready for the time when larger volumes of data will be generated.
SKA is a network of thousands of radio antennas, 197 of them located in South Africa and more than 1.3 lakh in Australia, designed to function as one single unit that will make it the world’s largest radio telescope. 
The first results have come just about six months after the first antennas in the SKA-Low array were installed in western Australia.
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