Space telescopes could produce time-lapse videos of black holes within '10 to 15 years'

Astronomers at the Event Horizon Telescope (EHT) revealed this image of supermassive black hole Sagittarius A* in May. Photo / National Science Foundation

Scientists are hoping to launch telescopes into space "in 10 to 15 years" to take time-lapse videos of black holes, an expert has said.

The videos will capture how the ultra-dense objects morph gravity and light over a period of several months. Astronomers hope to be able to use this to unpick the origins and mechanics of these mysterious celestial behemoths that dictate so much of the universe.

A supermassive black hole called Messier 87* was imaged in 2019 by the Event Horizon Telescope (EHT) team and the same group then turned their lens to the Milky Way's core, publishing the first-ever image of Sagittarius A*, the black hole our galaxy orbits around, last month.

Astronomers now hope to send telescopes into space to expand the scope of the EHT, as the system works by connecting telescopes around the world and turning the globe into one big "virtual telescope".

Messier 87* required seven telescopes, while the Milky Way's black hole needed eight.

'New and improved images'

But by adding more telescopes, both terrestrial and in orbit, the team will be able to gather more data and get sharper, less blurry photos which will shed new light on the dynamics and evolution of black holes.

Dr Ziri Younsi, UCL astronomer and scientist on the Event Horizon Telescope (EHT), said at the Cheltenham Science Festival that the next phase of the EHT is currently using 11 telescopes on Earth to get new and improved images of both the imaged black holes.

The data for this was gathered earlier this year, Younsi said, and tens of petabytes of data are currently stored by the team, awaiting analysis.

Younsi said it will take a number of years for this process to be refined and the finished product published for the public to see.

"We need more telescopes. So this year, we've got much better data, it's going to take us about three years to make an image but it will be a lot sharper," he said.

"So the contrast between the brightest features and the dimmest features will be much more crisp and then you can measure that much more accurately."

But beyond the immediate future, the EHT team needs to widen the aperture of their virtual telescope as much as possible.

"Extra telescopes in space will be connected to those on Earth as well. One of the challenges is how to establish a stable quality connection," Younsi said after his talk.

"We want to wirelessly transmit the data so we are thinking about putting a satellite in orbit that can receive the signal."

One possibility is putting satellites in orbit around Earth, but these will only be facing the night sky for a few hours a day before being blocked by the Earth itself. Another route is to use the Lagrange points around Earth, where a craft can remain stable indefinitely.

One such point, L2, is currently occupied by the James Webb Space Telescope, which Younsi revealed will be used by the EHT team in the next few years.

"The next generation of the event horizon telescope, which is a project I am involved with, we're already going to be working with James Webb," he said.

'One big telescope'

Some experts are aiming even higher and want to turn the entire Solar System into one big telescope by sending probes to the outer reaches of our Sun's orbit.

"People talk about having one the size of the solar system. Literally, like where Voyager is now," Younsi said.

The two Voyager crafts are the most distant man-made objects after exiting the Solar System following their launch in the 70s.

But the team is keen to move to videos as soon as possible, as they will show much more detail on how the black holes work and behave.

"They won't be a video in the conventional sense of 30 frames per second, but what they will show is like how the black hole is changing on the timescale of weeks to months, so it's like a time-lapse," the EHT astronomer said.

Earth-based videos will be ready in five years, Younsi believes, but the goal is to get the space telescopes working to this end down the line.

"I'd say 50 years from now, the technology will definitely be there and we will have stuff in space. It's something we're going to do in the next 10-15 years, for sure," Younsi said.