Construction of World’s Largest Radio Telescope Begins

Scientists will use its instruments to study the early universe

An artist's rendition of the telescope's dishes on the left and the telescope's antennae on the right.
A composite of the SKA telescopes that combines real images with an artist's impression.  SKAO

Construction for the Square Kilometer Array (SKA), the world’s largest radio telescope, began Monday.

The telescope will consist of instruments on two continents: around 131,000 antennae will make up the SKA-Low telescope in Australia, while 197 dishes will comprise the SKA-Mid telescope in South Africa, according to Nature NewsSarah Wild.

Scientists will use the highly sensitive instruments to study the early universe, dark energy and the expansion of the universe, per the Guardian’s Donna Lu.

The telescope “will be one of humanity’s biggest-ever scientific endeavors,” Philip Diamond, the SKA Observatory’s director-general, tells the Agence France-Presse (AFP).

The Australian telescope will consist of more than 500 arrays, each made up of 256 antennae, per Nature News. Together, the arrays will function as a radio telescope with a lens covering nearly 100 acres, according to Live Science’s Stephanie Pappas.

The SKA-Low telescope will detect radio waves with low frequencies (hence its name) between 50 and 350 megahertz, per Space.com’s Tereza Pultarova.

“[SKA-Low’s] sensitivity will allow us to observe the distant universe in much more detail than anything we’ve done so far,” Douglas Bock, director of space and astronomy at the Commonwealth Scientific and Industrial Research Organization in Australia, tells Nature News. “This is particularly exciting because we know so little about the first billion years of the universe.”

The array will sit on land of the Indigenous Wajarri Yamaji, who signed a land-use agreement stating that the construction would not take place on cultural sites, per Live Science.

“Once they’ve started construction, there are opportunities for Wajarri people to be involved in employment and commercial opportunities,” Des Mongoo, a Wajarri Yamaji community member, tells Nature News.

The SKA-Mid dishes, each 50 feet across, will detect radio waves between between 350 megahertz and 15.4 gigahertz, per Space.com. The dishes will span 93 miles, according to Live Science. SKA-Mid will also include the 64-dish MeerKAT telescope, which has already been built, per Nature News.

A giant, white dish that detects radio waves
A prototype for one of the dishes at the South Africa site.  Gerhard Swart/SKAO

Scientists place the telescopes in remote locations so that radio waves made by humans don’t interfere with the measurements of space, per Live Science.

The telescope’s size and the range of frequencies it can observe will allow it to gather detailed data on faint, distant signals.

“To put the sensitivity of the SKA into perspective, the SKA could detect a mobile phone in the pocket of an astronaut on Mars, 225 million kilometers away,” Danny Price, a radio astronomer at the Curtin Institute of Radio Astronomy, tells the AFP.

Plans to construct the telescope started 30 years ago, per Space.com.

“The SKA is going to contribute to so many areas of astronomy,” Shari Breen, the observatory’s head of science operations, tells the BBC’s Jonathan Amos.

Scientists are expected to conduct the first observations in 2024 using four dishes and six antenna arrays, according to the BBC. The goal is for construction to be complete by the end of the decade, per Space.com