For more than 400 years, telescopes have helped answer some of humanity’s biggest questions.
As well as making far-off objects appear closer, our understanding of the universe would be,
well, pretty non-existent if it weren’t for this technology.
Having evolved from simple spy glasses - the sort of thing a pirate would use - the most
advanced telescopes that we have today are somewhat bigger. OK, they're quite a bit bigger.
They’ve let us gather more knowledge of what goes on outside our planet than ever before.
But there’s still so much we don’t know - and to find out what really happened when
the galaxies were formed, or if there is other life out there we need to try something quite different.
Which is exactly what this new multinational megaproject plans to do.
Set to become the world’s largest radio telescope it’s currently being constructed
in both South Africa and Australia - yes, you heard that right - and it could unlock
some of the greatest discoveries of all.
Now when we talk about a radio telescope being built on two continents at the same time you’d
be forgiven for wondering what on earth we’re on about. So let’s go back a bit.
First of all, what’s a radio telescope?
Well, the sort of telescope you might use at home to look at the Moon or spy on your
neighbours - that’s an optical telescope.
They use mirrors or lenses to focus or bend light as it comes in through the opening,
known as an aperture.
But they don’t have to be small. Giant observatories with optical telescopes have been around since
the 19th century and there’s now a new one being built in Chile - you can see why they’ve
called it the Extremely Large Telescope.
Radio telescopes on the other hand study much longer wavelengths than visible light.
This means they can detect invisible gases and reveal whole new areas of space that optical
telescopes can’t see - because with those, cosmic dust often gets in the way.
Radio telescopes usually consist of large dishes that focus radio waves onto a receiver,
which then send signals for astronomers to study.
Some take the form of one big dish, like the massive Arecibo Observatory in Puerto Rico
- which sadly collapsed in late 2020.
Others are made up of several smaller dishes, like this one in New Mexico which has another
super imaginative title - the Very Large Array.
These telescopes have been used to make key discoveries in distant galaxies, observe black
holes, and - in the movies at least - host epic fight scenes and contact aliens.
If you think those are cool, you haven’t seen anything yet.
Work has just begun on the largest and most ambitious facility of its kind ever attempted
- the SKA Observatory.
It’s got nothing to do with Jamaican music - in this case, SKA stands for Square
Kilometre Array, referring to the total collecting area that all the various equipment will take up.
In case you’re wondering, that’s over three-and-a-half times the size of LA’s
massive new SoFi Stadium.
Part of the reason it’s so big is the system is divided into two main elements -
split across separate continents - which aim to detect tiny signals from deep space - some
from the very dawn of our universe.
“Part of the big issue in terms of what we’re trying to understand is the signals
we’re trying to detect are very faint and on top of those are
a range of different types of interference.
A key driver in particular is trying to get away from as much of that as possible.”
On one site in South Africa, almost 200 dishes will collect mid-frequency d​​ata.
Meanwhile in Australia more than 130,000 special antennas will gather low-frequency data.
Information from both places will then come together at several regional centres, where
powerful data processing will create images from the amplified signals.
Overseeing everything is a team of specialists at SKA’s headquarters -
thousands of miles away in the UK.
Next question, then - why have it in two parts, and in places so far away from each other?
Well, these parts of South Africa and Australia actually have some of the lowest radio interference
anywhere in the world, and positioning elements in both those places gives it a catchment
area that effectively spans two continents.
“The site itself - both of them - are quite remote and spread out over a large region
so longest baselines are, say, 70km for the Western Australia site and up to 150km for South Africa.
One of the jokes of our site construction director is ‘if you’ve missed your toolbox
you’ve got 350km to travel to go back and get it’ so you’ve really got to do a lot
of planning in terms of what you need on site.”
And because there are established observatories at each site already, the teams can build
on these rather than starting from scratch, with all the information sent to a centralised core.
Here, the aim is to turn all of this into the highest resolution images ever achieved in astronomy.
The combined facility - that’s been in the making since the 1990s - will be over ten
times more powerful than existing telescopes.
It might be able to help us finally understand what happened at the beginning of our universe,
unlock the secret of dark energy, or discover more Earth-like planets.
But this means handling astronomical amounts of data. It’ll require some incredible processing
power and long-distance high-speed connections.
Each of the two SKA supercomputers will be as powerful as the best in the world - as
of 2019 - and the system will use enough optical fibre to stretch around the planet - twice.
At over USD $2BN, all of this doesn’t come cheap.
The three nations mentioned so far are the main ones involved and they’re covering
the biggest share of the costs - but China, Italy, the Netherlands and Portugal are all founding members too.
A further seven countries took part in the design phase, and Japan and South Korea
recently joined the fun.
In total, there are 500 engineers and over 1,000 scientists from 40 countries on the team.
“Because of our global assembly we’re basically taking advantage of the knowledge,
experience and industrial capacity of the various member countries.
Each of those is contributing components and
subsystems and we have to assemble all of those together – we have to first get them
to site, and that logistical aspect of it is quite a challenge – so transport and
shipping from all over the world.”
The new dishes are being designed and constructed in China - based on this prototype model completed in 2018.
They’ll then join the 64 MeerKAT dishes that already exist at the South African site
- though the new ones are larger, lighter and less expensive to build.
A scaled-down version of the huge network of antennas that will spread across the Outback
has also been built at a radio observatory in Western Australia.
Although they’re not that different to regular TV antennas in design, their electronics are
far more sensitive - and they need to be to capture radio waves from space.
It’s worth noting that because these can be easily moved around and expanded, this
part of the system is highly flexible.
Contractors are now being appointed in Australia for all kinds of jobs - like the various high-tech
buildings, an airstrip and road, and fibre and power connections between the antenna stations.
The indigenous owners of the land, the Wajarri Yamatji, are supporting the project and look
set to be involved in the build.
Construction on the whole facility will run until 2028, but the first operations can begin
as soon as enough dishes and antennas are installed to start receiving signals.
That’s expected to be around 2024.
When it fully completes, SKA plans to have a lifetime of at least 50 years.
With remarkable progress made in space exploration and discovery in recent decades, it’s hoped
that SKA will be the tool that enables the next major leap forward.
“When you build an exploratory instrument like the SKA, what you provide is a broad
capacity for existing questions but it also allows you to begin to - because of that sensitivity
and resolution - answer questions you don’t know yet that might arise.”
This is a 50-year operation plan for the observatory - over that time we’re gonna learn a lot.”
While overcoming the problems here on Earth remains our biggest priority, learning more
about our place in the universe is crucial for our future too, and with this new tool
in our arsenal, who knows what we’ll find.
If you enjoyed this video and want your very own telescope to see where construction is
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