Eye on the SKA will enable us to map the entire universe

In the coming decades, humans will, for the first time, have comprehensive maps of the universe, says Roy Maartens, professor and research chair in cosmology at the University of the Western Cape.

“If you have surveys [of the skies] from today to, say, 10-billion years ago, we can make huge, moving maps of the universe.”

On Monday, in a series of scientific papers published on astrophysics website arxiv.org, an international team of scientists laid out plans for these gigantic surveys, with the Square Kilometre Array (SKA) playing a vital role.

The SKA, which will have thousands of dishes and antennas in Australia and Africa, will be the largest radio telescope built, and one of the biggest pieces of scientific infrastructure on Earth. 

The core of the telescope will be in South Africa, in the Northern Cape, and will attempt to answer some of humanity’s most enigmatic questions, such as: Is there other life in the universe, how do galaxies form and what is dark energy?


Grand plans
Working groups in the international SKA Organisation are developing science cases and will use the telescope to try to answer these kinds of questions.

Maartens, who is head of the Cosmology Science Working Group of the SKA project, says: “There are six other working groups, and there have been chapters coming from all of them.”

His group decided to publish theirs all at once. About 130 papers have been published so far.

The first phase of the SKA – which will incorporate South Africa’s 64-dish MeerKAT telescope and Australia’s ASKAP – is expected to be complete in 2023, and the second phase – which will be 10 times larger than the first – in the “late 2020s”, the SKA Organisation said on Monday.

“It’s rewarding to see all these papers being published,” says Robert Braun, the SKA Organisation’s science director. “The wide range of science covered in them is testimony to the SKA’s potential as a 21st century facility to revolutionise many areas of study in astrophysics, but also in physics, astrochemistry and beyond,” he says.

Guide to the stars
One area of science that the SKA and a number of other international experiments will investigate is mapping the universe. “The standard way to map the positions of galaxies is to painstakingly detect the faint radio signals from many individual galaxies, staring at them for long enough to measure properties like their distance,” the SKA Organisation said in a release. 

At the moment, researchers have mapped the position of only about a million galaxies, but by the late 2020s, they hope to have found almost a billion, the organisation said.

“Even before the billion-galaxy survey is built, phase 1 of the SKA will be able to produce maps of nearly the entire universe and the matter in it at different periods in time, using an innovative new technique called intensity mapping,” Maartens says. 

He points to the example of the map of the cosmic microwave background (CMB), residual thermal radiation thought to be from the Big Bang that permeates the universe. “With CMB, we have this exquisite map of the sky” but it is only a snapshot of the early universe, he says.

“In the coming decades … we will have something like the CMB [map] but at different slices of time – a three-dimensional map of nearly the whole universe.”

Maartens is careful to point out that other future survey experiments – such as European Space Agency’s Euclid satellite and the United States’ Large Synoptic Survey Telescope – will also create maps of the universe, although they will not quite match the depth and scale of the full SKA.

But it is difficult to pin down science cases. “Some of the science objectives will need to be modified,” says Maartens. “You want flexibility. You don’t want to constrain yourself by locking down on a few definite objectives – you have to be able to deal with unknowns.”

This is because of the importance of serendipity, when unexpected things that you do not know are discovered. “Science cases … explicitly talk about the discovery aspect,” he says.

Subscribe to the M&G

These are unprecedented times, and the role of media to tell and record the story of South Africa as it develops is more important than ever.

The Mail & Guardian is a proud news publisher with roots stretching back 35 years, and we’ve survived right from day one thanks to the support of readers who value fiercely independent journalism that is beholden to no-one. To help us continue for another 35 future years with the same proud values, please consider taking out a subscription.

Related stories

Government’s Covid-19 science mask is slipping

The government’s professed reliance on science to justify its response to the pandemic reveals both its overconfidence and its insecurities about getting citizens to cooperate

Inclusivity through innovation

Special Annual Theme Award: Materials for inclusive economic development

Why we need more women to work in water research

Investing more in women in science — particularly in the water and sanitation sectors — is imperative if we are to meet the sustainable development goals by 2030

African governments must invest in science for future growth

Allocating adequate funding to scientific research, development and innovation can have a positive effect on sustainable development

Build bond between science and society

New ideas and technologies can provide solutions but in unethical hands they can be dangerous

SKA could add time to flight path

The aviation sector is worried that rules about the radio spectrum in the skies above the project could affect the Jo’burg to Cape Town route
Advertising

Subscribers only

The shame of 40 000 missing education certificates

Graduates are being left in the lurch by a higher education department that is simply unable to deliver the crucial certificates proving their qualifications - in some cases dating back to 1992

The living nightmare of environmental activists who protest mine expansion

Last week Fikile Ntshangase was gunned down as activists fight mining company Tendele’s expansions. Community members tell the M&G about the ‘kill lists’ and the dread they live with every day

More top stories

Fifteen witnesses for vice-chancellor probe

Sefako Makgatho University vice-chancellor Professor Peter Mbati had interdicted parliament last month from continuing with the inquiry

Constitutional Court ruling on restructuring dispute is good for employers

A judgment from the apex court empowers employers to change their workers’ contracts — without consultation

Audi Q8: Perfectly cool

The Audi Q8 is designed to be the king in the elite SUV class. But is it a victim of its own success?

KZN officials cash in on ‘danger pay for Covid-19’

Leadership failures at Umdoni local municipality in KwaZulu-Natal have caused a ‘very unhappy’ ANC PEC to fire the mayor and chief whip
Advertising

press releases

Loading latest Press Releases…

The best local and international journalism

handpicked and in your inbox every weekday