Nepedia
Back to Discover
Advanced Reader
🚀

Square Kilometre Array

space Maturity 9-11 Next article →

The Square Kilometre Array, known as the SKA, is a massive international radio telescope project.

SKA participants map
SKA participants map

Unlike traditional telescopes that capture visible light, the SKA listens to radio waves from deep space. This project is an intergovernmental effort to build a tool of unprecedented power. The name refers to the total collecting area the telescope will eventually have. This target is approximately one square kilometre of surface area. The SKA will be 50 times more sensitive than any existing radio instrument. It will also survey the sky more than ten thousand times faster than previous technology.

SKA sparse array big
SKA sparse array big

The SKA operates using complex scientific techniques to simulate a single, massive instrument. It uses aperture synthesis to combine signals from thousands of small antennas spread across a wide area. This technique allows the array to act as one giant telescope. It also uses very-long-baseline interferometry to link with other radio telescopes located thousands of kilometres away. This process provides extremely high angular resolution, which means very clear images. The telescope is divided into two main sub-arrays based on frequency. The SKA-low array uses a phased array of low-frequency antennas. These look like "Christmas-tree" antennas and cover 50 to 350 MHz.

SKA dense array big
SKA dense array big

The second part is the SKA-mid array, which uses several thousand dish antennas. These dishes cover a higher frequency range from 350 MHz to 14 GHz. The SKA-mid antennas will likely use an offset Gregorian design. This design features a height of 15 metres and a width of 12 metres.

SKA dishes big
SKA dishes big

The physical layout of the project includes three distinct regions. A central region contains the main cores in South Africa and Western Australia. This core contains about half of the total collecting area. A mid region extends out to 180 km with randomly placed dishes. An outer region reaches up to 3000 km using five spiral arms.

SKA cores big
SKA cores big

The history of the SKA began with a concept in 1991. An international working group was established in 1993 to move the idea forward. In the early planning stages, China proposed a different project called KARST. They suggested using natural limestone depressions in their southwestern provinces for large dishes. Eventually, the project became an independent, not-for-profit intergovernmental organization. The Square Kilometre Array Observatory, or SKAO, was founded in Rome in March 2019. The headquarters for the SKAO was placed at the Jodrell Bank Observatory in the United Kingdom.

At Jodrell Bank Observatory 2018 040
At Jodrell Bank Observatory 2018 040

Building such a massive system requires many different nations to work together. The SKAO consortium was started by seven founding members in 2019. These included Australia, China, Italy, the Netherlands, Portugal, South Africa, and the United Kingdom. Since then, the membership has grown to 14 countries. Recent members include Switzerland, Spain, Canada, Germany, and India. India joined the project in early 2024 with a financial commitment of ₹1,250 crore. The construction phase officially started on 5 December 2022. This event was celebrated by delegations from the participating countries in both Australia and South Africa.

The project is being built in two main phases. The current phase is called SKA1, or simply SKA. This phase aims to provide an operational array for scientific use. A possible future phase is called SKA2, which would be significantly larger. The SKA-low part is being built in the Murchison region of Australia. This site is on the traditional lands of the Wajarri Aboriginal people. The area is called _Yulgarrin_, which means "quiet" in the Wajarri language. This location was chosen because it is a radio-quiet zone. This quietness is necessary to prevent interference from other electronic signals.

Square Kilometre Array Organisation members
Square Kilometre Array Organisation members

The SKA is a major technological and economic undertaking. In 2014, the project was estimated to cost €1.8 billion. This included €650 million for the first phase alone. Some reports suggest the total project value is around A$3 billion. Because the project has lasted nearly 30 years, it has faced many delays and rising costs. To handle the massive amounts of data, scientists are looking at new supercomputing solutions. The Department of Atomic Energy in India and UK Research and Innovation are investigating these facilities. These computers will be essential to process the signals the SKA hears from the cosmos.

698 words

Where will your curiosity go next?

Keep exploring at your chosen reading level.

🖼️ Images & Media (10)
File:At Jodrell Bank Observatory 2018 040.jpg
At Jodrell Bank Observatory 2018 040.jpg
File:SKA participants map.svg
SKA participants map.svg
File:SKA sparse array big.jpg
SKA sparse array big.jpg
File:SKA dense array big.jpg
SKA dense array big.jpg
File:Square Kilometre Array Organisation members.svg
Square Kilometre Array Organisation members.svg
File:SKA-scanner.jpg
SKA-scanner.jpg
File:CSIRO ASKAP 2010.jpg
CSIRO ASKAP 2010.jpg
File:2017 meerkat 01.png
2017 meerkat 01.png
File:SKA dishes big.jpg
SKA dishes big.jpg
File:SKA cores big.jpg
SKA cores big.jpg
More to explore

What is Nepedia?

A free, ad-free encyclopedia for children. Every article is written at five reading levels, so the same page works for a five-year-old and a fifteen-year-old — use the level switcher above to see this one change. No account needed to read.