Twenty years after the project began, scientists think they are now just weeks away from receiving their first picture of a black hole.
The numbers behind the creation of the Event Horizon Telescope (EHT) are mind boggling enough, let alone the thought of what it might see on April 5 when it’s trained on Sagittarius A*, the super-massive black hole at the centre of our galaxy.
It’s 26,000 light years from Earth. Even though its “edge” is 20-odd million kilometres across, EHT team members say seeing it is still like trying to pinpoint a grapefruit on the Moon.
The “edge” is more commonly known as the “event horizon”. It’s the point at which even light cannot escape the force of gravity.
Ten years ago, the EHT’s array of radio telescopes around the world began collecting the data which, when combined, make the EHT a kind of “virtual telescope”. But the pictures it takes are very real, and recently, the addition of the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile to the network brought the big day forward.
“We’ve been fashioning our virtual telescope for almost two decades now, and in April we’re going to make the observations that we think have the first real chance of bringing a black hole’s event horizon into focus,” project leader Sheperd Doeleman told the BBC.
Those 20 million kilometres of black hole have a mass of around four million suns, yet Sagittarius A* would fit within Mercury’s orbit. When a picture of what that actually looks like emerges, according to Einstein’s theory of general relativity, it should be something like this:
But if they don’t, “we would have to reassess the theory of gravity”, Doeleman said.
So, one of those pivotal moments in science, you might say.
But while all the action will take place between April 5 and 14, there’ll be an agonising wait until at least the end of the year before humanity gets its first real look into a black hole.
Up to 10,000 laptops worth of data have to be collected and flown to MIT’s Haystack Observatory just outside Boston, Massachusetts, before the crunching begins.
Some of the hard-drives have been filled with helium so they can withstand the low air pressure from observatories as high as 5000m above sea level.
When combined, the EHT produces 2000 times more detail than the Hubble Space Telescope.
You can read more about what else they hope to see at the BBC.