WASHINGTON (CN) – Unveiling the first ever photograph taken of a black hole, scientists celebrated a groundbreaking moment in astrophysics Wednesday morning.
At a series of coordinated press conferences held around the globe, researchers with the National Science Foundation and the Event Horizon Telescope revealed an image of a ring of light that captured the black hole at the center of Messier 87 (M87), one of the largest galaxies in the universe. The black hole resides 55 million light-years from Earth.
As put by astrophysicist Sheperd Doeleman, capturing this image is the equivalent of being able to read the date on a quarter in Los Angeles from Washington, D.C.
“We’ve exposed part of the universe that we thought was invisible before,” said Doeleman, who is project director of the Event Horizon Telescope and works with the Center of Astrophysics.
The ring of light shows the matter on the black hole’s event horizon, the theoretical boundary that marks the point beyond which no light or radiation can escape.
Doeleman explained that this matter shines very brightly because it is superheated.
This photo is the result of $28 million in investments from the NSF and more than a decade of work by 20 institutions and more than 200 people from across the globe. It was produced by connecting eight ground-based telescopes around the world to virtually create an Earth-sized scope more powerful than any single telescope on earth.
Scientists say the image was captured over the course of a few days in April 2017. Dan Marrone, a co-investigator with the telescope team, noted that it involved years of preparation.
The team telescopes used to capture the image were made ready with “tens of crates of hardware” and atomic clocks, he said. Telescopes located in Chile and at the South Pole were among the most challenging to outfit, Marrone added.
After the hardware was installed, the team spent years testing communications between the telescopes. They had the fortune of having good weather in all locations where telescopes were located and scanning M87. The images taken amounted to around 5 petabytes of data, which was put on more than half a ton of hard drives.
This amount of data is the equivalent to “the entire selfie collection over a lifetime for more than 40,000 people,” said Marrone, an experimental astrophysicist at the University of Arizona.
After obtaining the image, the scientists wrote six academic papers on the subject, which were published today in a special issue of The Astrophysical Journal Letters.
The image of the black hole is particularly significant in that the circular ring of light around the hole verifies Albert Einstein’s theory of relativity, put forth in 1915 to explain the laws of gravity and their relation to natural forces. As black holes suck in almost anything in their paths, including stars, planets, gas and dust, the size and shape of the shadow surrounding the hole verifies Einstein’s gravity predictions.
“In general relativity, radio waves fall just as apples do,” said astrophysicist Avery Broderick, a member of the Event Horizon board. “Typically this effect is exceedingly small, but black holes are gravity run amuck. The radio waves we see in these first images orbited the black hole before beginning their 55 million year journey toward us.”
Avery noted that this causes the dark shadow or silhouette cast by the black hole’s event horizon. Gravity alone determines the size and shape of this shadow.
“What we learn from one necessarily applies to the other,” Avery said.
He emphasized that this image marks the discovery that, despite varying in mass, all known black holes will follow this pattern.
Sera Markoff, an astrophysicist at the University of Amsterdam, said that the Event Horizon photo provides insight into how black holes help shape the universe.
By comparing M87 observations to those of a dormant black hole at the Milky Way’s galactic center called Sagittarius A*, Markoff said scientists hope to learn how universe creation works.
“By looking at two black holes at opposite extremes of this activity range especially combining this with multi-wave length information, we can better understand the ebb and flow of influence of black holes in the long course of our history in the universe,” said Markoff, who is a member of the Science Council at Event Horizon Telescope.
The image is a composite. Doeleman said they hope to make the image, which appears somewhat fuzzy, a little sharper by adding new telescopes and using algorithms. The more data scientists get, the sharper the image will become.
Marrone echoed this: ”The higher frequency observations will be very exciting.”
NSF director France Cordova said it brought tears to her eyes when she saw the image for the first time at the public reveal today.
“As an astrophysicist this is a thrilling day for me,” she said.
Cordova noted that black holes are discussed so often, it’s easy to forget that, until this image was captured, no one had actually seen one.
She also emphasized how international collaboration was critical to this event.
“The EHF would not have been impossible without collaboration because no single telescope on earth could see the black hole event horizon,” Cordova said.
This Friday a documentary that follows the Event Horizon Telescope over the last two years, called “Black Hole Hunters,” will premier on the Smithsonian Channel at 9 p.m. Eastern.