A photo of the black hole in the center of M87. Photo: Event Horizon Telescope collaboration et al.
For the first time in history, we know what a black hole looks like, specifically the supermassive black hole lurking in the center of a galaxy called Messier 87 (M87).
Why it matters: A new photo, taken by the Event Horizon Telescope, represents humanity's first real look at a black hole, and it could fundamentally alter how we understand these objects and test even the most basic laws of physics.
"We have now seen what we thought was unseeable," EHT project director Sheperd Doeleman said during a press conference in Washington on Wednesday. "We have seen and taken a picture of a black hole."
The black hole in M87’s heart is 6.5 billion times the mass of our sun and thought to be almost the size of our entire solar system, astrophysicist Sera Markoff said.
Details: The EHT is a group of radio observatories that stretch around the globe from the U.S. to Greenland and even the South Pole, creating a virtual telescope the size of Earth.
- Those observatories worked in tandem with one another to look into the heart of M87, revealing the black hole in its center. But getting this photo wasn't easy.
- Black holes are so dense that not even light can escape them, making it impossible to directly image the incredibly massive objects.
- Instead, the EHT effectively revealed the shadow of a black hole illuminated by the matter on the edge of the object's event horizon — the area near the black hole known as the "point of no return," where the gravity is so great that nothing can escape.
- The black hole revealed on Wednesday has a mass calculated to be 6.5 billion times that of the sun, scientists said.
The big picture: The photo shows that the black hole at the center of M87 “does indeed appear to have the definition feature of a black hole — the event horizon, the point of no return,” EHT scientist Avery Broderick said. The EHT photo also seems to, yet again, validate Albert Einstein's general theory of relativity.
- The image confirmed that Einstein's predictions about the size and shape of black holes are correct and "determined by gravity alone," Broderick added. "Today, general relativity has passed another crucial test."
- "It has verified Einstein’s theory of gravity in the most extreme laboratory for it," Doeleman said.
The EHT observations are also helping scientists figure out how black holes generate huge jets of radiation that structure the galaxies around them, something they've only been able to simulate on supercomputers.
- "We always thought that black holes were behind these structures, driving these engines, but we never knew," Markoff said.
How they did it: All of the radio telescopes working with the EHT used atomic clocks to sync up observations of the black hole. But there was too much data to send over the internet. Instead, the team had to ship the data by mail to one facility where it could be processed by a supercomputer.
What's next? Eventually, the EHT collaboration hopes that they'll be able to launch a radio telescope to space, allowing them to get an even clearer picture of a black hole.
- "World domination is not enough for us, we also want to go into space," Doeleman said.
The researchers are also working on taking a clear photo of the black hole in the center of the Milky Way.
What they're saying: "It did bring tears to my eyes. This is a really big deal," said National Science Foundation director France Córdova.
“There was a great sense of relief to see this but also surprise,” Doeleman said. “We saw something so true, we saw something that really had a ring to it. It was just astonishment and wonder, and I think that any scientist in any field would know that to see something for the first time."