The largest radio telescope will be built on two different continents and will cost about 2 billion euros.

By Amandine Galama – 10th grade

After 30 years of development, construction has begun on what, when completed, will be the world’s largest radio telescope. The SKA, Square Kilometer Array, will be built on two different continents, and has been called one of the biggest scientific projects of the 21st century. When finished, the telescope will be used to study dark energy, uncover why the universe is expanding, and maybe even search for extraterrestrial life forms.

The telescope will be built on an effective area of hundreds of thousands of square meters. To get that much space, the telescope will be built in two different countries, on two separate continents. Part of this massive telescope will be built in the remote Wajarri country in Australia. This portion of the telescope, called SKA-Low, due to its sensitivity to low-frequency radio signals, will consist of 131,072 antennas. The other part of the telescope, will be called SKA-Mid, and will be in South Africa’s Karoo region. It will be an array of traditional “dishes”, also known as parabolic antennas. 

When completed, the telescope will be eight times more sensitive than comparable existing telescopes, and able to map the sky 135 times faster. It will operate on a frequency range of 50 megahertz to 25 gigahertz, which will enable the telescope to detect signals from billions of years ago. This means that the telescope will be able to detect very faint signals from the first few hundred million years after the Big Bang. One of the goals of building this telescope is to discover the full history of the most abundant element in the Universe, hydrogen. 

The Square Kilometer Array is expected to be finished in 2028 with a total area of just under 500,000 square meters, but parts of the telescope will already by operational as soon as 2024, when six antenna stations in South Africa and four dishes will have been set up, and made to work together as a basic telescope. 

Though work on the telescope is expected to be completed in 2028, the telescope is being built in such a way that it could become bigger. The telescope costs roughly 2 billion euros, and is funded by governments as well as international agencies. Currently, the member countries of the project are South Africa, Australia, the Netherlands, the United Kingdom, China, Italy, Portugal and Switzerland, with France, Germany and Spain planning to join soon. The UK , where the project’s headquarters are located, is currently the largest contributor to the project, paying 15% of the construction costs. If more countries join in and help fund this project it could grow to the desired one million square meters.