In a moment of great gravity, the world on Wednesday finally got a glimpse of a black hole — an object so dense that nothing, not even light, can escape from it.
The first image of a black hole and its fiery halo was released by Event Horizon Telescope astronomers — and described the most direct proof of their elusive existence.
The globe-spanning network of eight radio telescopes focused on the superm assive m onster in the galaxy M87 to create the first-ever picture of a black hole.
The result was announced at simultaneous news conferences in Washington, DC, Brussels and five other locations.
Event Horizon Telescope (EHT) trained its sights on both M87’s black hole and Sagittarius A*, the superma ssive black hole at the center of the Milky Way, the spiral galaxy that contains our solar system.
But it turns out that it was easier to capture M87’s black hole, which is more than 50 million light-years from Earth in the constellation Virgo — about 2,000 times as far as Sagittarius A*.
It is also about 1,000 times as m assive as the Milky Way’s giant, which weighs the equivalent of roughly 4 million suns. That extra size nearly balances out M87’s distance.
“The size in the sky is pretty darn similar,” said EHT team member Feryal Özel.
Of all the f orces in the universe that we cannot directly observe — including dark energy and dark matter — none has f rustrated human curiosity as much as black holes.
The star-devouring m onsters were predicted by Albert Einstein’s theory of general relativity, as solved in 1915 by the German physicist Karl Schwarzschild.
That theory ascribes gravity to the warping of space and time by matter and energy, predicting that a sufficiently compact mass can deform spacetime to form a black hole.
At the same scale of compression, Earth’s mass would fit inside a thimble, while the sun’s would be a mere 4 miles from edge to edge.
“Over the years, we accumulated indirect observational evidence,” said Paul McNamara, an astrophysicist at the European Space Agency and project scientist for the LISA mission that will track mass ive black hole mergers from space.
“X-rays, radio waves, light — they all point to very compact objects, and the gravitational waves confirmed that they really are black holes, even if we have never actually seen one,” McNamara told AFP.
Scientists can see how the strong gravity affects the stars and gas around the black hole. When a black hole and a star are close together, the high-energy light that is produced can be observed using satellites and telescopes in space.
There are two types of black holes.
The garden-variety types are up to 20 times more m assive than the sun and form when the center of a very big star collapses in on itself.
Then there are the so-called superm assive bl ack holes, which are at least a million times bigger than the sun. Both Sag A* and M87 fall into this category.
The Event Horizon Telescope is unlike any stargazing instrument ever created.
“Instead of constructing a giant telescope, we combined several observatories as if they were fragments of a giant mirror,” Michael Bremer, an astronomer at the Institute for Millimetric Radio Astronomy in Grenoble, told Agence France-Presse.
Eight such telescopes — in Hawaii, Arizona, Spain, Mexico, Chile and the South Pole — focused on Sag A* and M87 on four different days in April 2017.
Together, they form a virtual telescope more than 7,000 miles — about the diameter of the Earth. Data collected by the instruments was to be collated by supercomputers at MIT in Boston and in Bonn, Germany.
“The imaging algorithms we developed fill the gaps of data we are missing in order to reconstruct a picture,” the team said on its website.
Astrophysicists not involved in the project, including McNamara, are eagerly awaiting the findings to see if they challenge Einstein’s theory of general relativity, which has never been tested on this magnitude.
The huge black hole at the heart of galaxy Messier 87.