Astronomers have captured the first image of a black hole, heralding a revolution in our understanding of the universe’s most enigmatic objects. The picture shows a halo of dust and gas, tracing the outline of a colossal black hole, at the heart of the Messier 87 galaxy, 55m light years from Earth. Quick Guide What are black holes? Show Black holes were first predicted by Einstein’s theory of general relativity, which reimagined gravity as the warping of space and time by matter and energy. The equations predicted that, beyond a certain threshold, when too much matter or energy is concentrated in one place, space and time collapse, leaving behind a sinkhole through which light and matter can enter but not escape. At first these were thought to be mathematical oddities, rather than real astronomical objects, but in the past century overwhelming evidence has confirmed that black holes are out there. The edge of the black hole is defined by its so-called event horizon. This is the point at which escaping would require something to travel at faster than the speed of light – which as far as we know nothing does – so it is the point of no return. Black holes are surrounded by an accretion disk of dust and gas, orbiting at close to the speed of light. A lot of this material is destined for oblivion, although some of it is ejected as powerful jets of radiation. Was this helpful? Thank you for your feedback. The black hole itself – a cosmic trapdoor from which neither light nor matter can escape – is unseeable. But the latest observations take astronomers right to its threshold for the first time, illuminating the event horizon beyond which all known physical laws collapse. The breakthrough image was captured by the Event Horizon telescope (EHT), a network of eight radio telescopes spanning locations from Antarctica to Spain and Chile, in an effort involving more than 200 scientists. Sheperd Doeleman, EHT director and Harvard University senior research fellow said: “Black holes are the most mysterious objects in the universe. We have seen what we thought was unseeable. We have taken a picture of a black hole.” 01:47 Astronomers reveal first-ever picture of a black hole – video France Córdova, director of the US National Science Foundation and an astrophysicist, said that the image, which she had only seen as it was unveiled at the press briefing she was chairing, had brought tears to her eyes. “We have been studying black holes for so long that sometimes it’s easy to forget that none of us has seen one,” she said. “This will leave an imprint on people’s memories.” The image gives the first direct glimpse of a black hole’s accretion disc, a fuzzy doughnut-shaped ring of gas and dust that steadily “feeds” the monster within. The EHT picks up radiation emitted by particles within the disc that are heated to billions of degrees as they swirl around the black hole at close to the speed of light, before vanishing down the plughole. The halo’s crescent-like appearance in the image is because the particles in the side of the disc rotating towards Earth are flung towards us faster and so appear brighter. The dark shadow within marks the edge of the event horizon, the point of no return, beyond which no light or matter can travel fast enough to escape the inexorable gravitational pull of the black hole. Black holes were first predicted by Einstein’s theory of relativity – although Einstein himself was sceptical that they actually existed. Since then, astronomers have accumulated overwhelming evidence that these cosmic sinkholes are out there, including recent detection of gravitational waves that ripple across the cosmos when pairs of them collide. But black holes are so small, dark and distant that observing them directly requires a telescope with a resolution equivalent to being able to see a bagel on the moon. This was once thought to be an insurmountable challenge. The EHT achieved the necessary firepower by combining data from eight of the world’s leading radio observatories, including the Atacama Large Millimetre Array (Alma) in Chile and the South Pole Telescope, creating an effective telescope the size of the Earth. When observations were launched in 2017, the EHT had two primary targets. First was Sagittarius A*, the black hole at the centre of the Milky Way, which has a mass of about 4m suns. The second target, which yielded the image, was a supermassive black hole in the galaxy M87, into which the equivalent of 6bn suns of light and matter has disappeared. The collaboration is still working on producing an image of the Milky Way’s black hole. “We hope to get that very soon,” said Doeleman. The success of the project hinged on clear skies on several continents simultaneously and exquisite coordination between the eight far-flung teams. Observations at the different sites were coordinated using atomic clocks, called hydrogen masers, accurate to within one second every 100 million years. And, on one night in April 2017, everything came together. “We got super lucky, the weather was perfect,” said Ziri Younsi, a member of the EHT collaboration who is based at University College London. The sheer volume of data generated was also unprecedented – in one night the EHT generated enough data to fill half a tonne of hard drives. This meant waiting for half a year for the South Pole data, which could only be shipped out at the end of Antarctic winter. The observations are already giving scientists new insights into the weird environment close to black holes, where gravity is so fierce that reality as we know it is distorted beyond recognition. At the event horizon, light is bent in a perfect loop around the black hole, meaning if you stood there you would be able to see the back of your own head. The observations also provide one of the most stringent tests to date of Einstein’s theory of general relativity: this predicts a rounded shape of the black hole’s halo, in line with what EHT has observed.<doc-sep>Scientists have spent decades studying them, but Wednesday provides our first-ever image of a black hole. The National Science Foundation hosted a morning press conference featuring scientists from around the world to release the picture, albeit fuzzy, of a black hole. The image was captured using the Event Horizon Telescope, an international collaboration created to show a black hole. Here's everything you need to know about black holes. What is a black hole? They are collapsed stars with gravity so strong not even light can escape. According to NASA, because no light can get out, people can't see black holes, which is why scientists use special tools like telescopes to spot them. The National Science Foundation says there are four types of black holes, ranging from tiny primordial black holes which emerged right after the Big Bang, to supermassive black holes like the one captured in the image released Wednesday which are way more substantial than our sun. When were they first discovered? Albert Einstein first predicted black holes as part of his theory of relativity in 1915. According to the Department of Astronomy at Cornell University, physicist John Wheeler was first credited with using the term black hole in 1967. Before then, black holes were sometimes referred to as "dark stars" or "frozen stars." How do scientists learn about black holes? NASA said since researchers can't "see" a black hole, they use tools to study how strong gravity affects nearby stars and gas. High-energy light is created when a black hole and star are close together, said NASA, and scientists can view it using satellites and telescopes. How did scientists capture an image of a black hole? Researchers used the Event Horizon Telescope, a collection of eight telescopes on five different continents specifically designed to peer at black holes. The EHT links the telescopes together to form a virtual telescope the size of Earth. The EHT takes the radio wave data from all eight telescopes and combines them into the image shown. So why does it look kinda blurry? Avery Broderick, an astronomy professor at the University of Waterloo in Ontario, Canada, said it's because the telescopes used reached a "fundamental resolution limit." The NSF said in a Medium post because of a black hole's intense gravity, you can't capture an image of the actual black hole, but light near the black hole's "point of no return." "What we are seeing is truly the silhouette of a black hole. This is what it is like to stare directly into the void." Contributing: Doyle Rice. Follow Brett Molina on Twitter: @brettmolina23.<doc-sep>The orange speckles in a new image from NASA's Chandra X-ray Observatory add another dimension to the first-ever image of a black hole . This supplemental picture offers a zoomed-out perspective of the same tremendously dense structure of the now-viral image, helping scientists learn more about what's happening in the black hole's neighborhood. The supermassive black hole starring in both pictures is located in the elliptical galaxy Messier 87. It's a behemoth; this black hole boasts a mass several billion times greater than that of Earth's sun. To offer a little more perspective about this structure and the powerful effect it has on the matter around it, scientists collaborating with the Event Horizon Telescope (EHT) captured a different view of this same target. They did so in tandem with EHT observations made in April 2017, according to a statement published the same day as the black hole picture. Related: Historic First Images of a Black Hole Show Einstein Was Right (Again) Related: How the Event Horizon Telescope Hunts for Black Hole Silhouettes NASA's Chandra X-ray Observatory spent 30,000 seconds watching the supermassive black hole at the center of Messier 87 during the April 2017 observing run by the Event Horizon Telescope (EHT). These X-ray data, in combination with the new radio image from the EHT released April 10, will help scientists learn more about high-energy emission as well as the physics of accretion and ejection at the black hole's event horizon. (Image credit: NASA/CXC/Villanova University/J. Neilsen) To capture the incredible image of a supermassive black hole's shadow, the EHT project gathered data from a global array of radio antennas. On Wednesday (April 10), the incredible feat of finally imaging this enigmatic structure astonished scientists and the public alike. But another instrument in space, Chandra, has been gazing at the black hole's home galaxy over the last two decades, collecting data in a different wavelength: X-rays. Astronomers had Chandra stare at Messier 87 (M87) for about 30,000 seconds, or roughly 8.3 hours, as the EHT dish network took its observations from the ground. The four ultrasensitive mirrors that Chandra carries in its orbit around Earth observed the X-ray radiation of multimillion-degree gas shrouding M87. The National Science Foundation funded the Event Horizon Telescope project, which successfully captured this picture, the first-ever image of a black hole using radio waves. These X-rays came from the high-energy particles the black hole was flinging into space. The material resulted in a jet shape which extends over 1,000 light years from the center of M87, Chandra representatives said in the statement. Viewers can observe the jet more clearly in the enlarged image inset. Black holes are superdense structures with tremendous gravitational pull, and past a black hole's threshold, the event horizon, even light cannot escape. Every galaxy is thought to host a supermassive black hole, like this one within M87, at its center. Scientists used NASA's Chandra X-ray Observatory to obtain data about the supermassive black hole at the center of Messier 87, an elliptical galaxy located 60 million light-years away from Earth, in the Virgo galaxy cluster. (Image credit: NASA/CXC/Villanova University/J. Neilsen)<doc-sep>A picture of a black hole is one of those great, self-negating concepts, like the sound of silence, the presence of absence or the lives of the dead. The nature of one refutes the other. But a picture of a black hole has arrived nonetheless — revealed Wednesday morning in simultaneous press conferences held in six different locations around the world. At those events — in Washington, Brussels, Santiago, Shanghai, Taipei and Tokyo — astronomers gave humanity its first look at the black hole at the heart of the Messier 87 (M87) galaxy, nearly 54 million light years from Earth. With that, astrophysics opened one more tiny crack in the wall of secrets that is the universe: The image reveals the black hole at the center of Messier 87, a massive galaxy in the nearby Virgo galaxy cluster. This black hole resides 55 million light-years from Earth and has a mass 6.5-billion times that of the Sun. National Science Foundation “We are delighted to report to you that we have seen what was thought to be unseeable,” said Shep Doeleman, Harvard University senior research fellow and director of the Event Horizon Telescope (EHT), at the announcement at Washington’s National Press Club. “We now have visual evidence. We know that a black hole sits at the center of the M87 galaxy.” True to the nature of the science, the picture does not show the black hole itself. The defining feature of all black holes is that they are so dense, generating a gravity field so powerful, that nothing, not even electromagnetic energy — which, of course, includes visible light — can escape their pull. What the picture reveals instead is the black hole’s so-called event horizon, the swirl of gas and dust and stars and light itself, circling the gravitational drain, before they’re sucked inside never, ever to reemerge. In April of 2017, a global web of eight radio telescopes located in six places (Chile, Mexico, Spain, Hawaii, Arizona and the Antarctic), the collective network that makes up the EHT, began surveying the Messier 87 black hole, as well as the black hole at the center of our own Milky Way galaxy. Seeing any sign at all of either formation was no small achievement. “The light from the M87 black hole has to travel for 60,000 years through its own galaxy, then for 55 million years across interstellar space,” said Doeleman. “Then it had to make it through our atmosphere, where the greatest enemy of the photons is water vapor.” For that reason, all of the telescopes are deployed in places where the air is generally dry and generally clear — though not always. Simple bad weather could stymie even the most sophisticated plans, but the EHT team caught a break. “We were very lucky,” said University of Arizona astronomer Dan Marrone, of the EHT team. “Our first three days of observing were some of the best we’ve ever seen.” The black hole at the center of our galaxy goes by the name Sagittarius A*. It has a mass equivalent to about 4.1 million of our suns. While that earns it the sobriquet “supermassive black hole” (more common black holes can be as small as five solar masses), it’s actually something of a pipsqueak as these things go. It measures perhaps 24 million miles across, or about a 50 billionth the size of the galaxy. Trying to take an image of that from the 26,000 light year distance at which the Earth sits from the center of the Milky Way is like trying to spot an orange on the surface of the moon—with the naked eye. (A picture of Sagittarius A* was not released Wednesday, but will be in the future.) The black hole at the center of M87, by contrast, has a mass equivalent to 6.5 billion suns, or 1,585 times bigger than our own black hole. But at 2,700 times the distance, it was even harder to see. Never mind the orange on the moon, Doeleman said: “This is the equivalent of being able to read the date on a quarter in Los Angeles, standing here in Washington, D.C.” One thing that made the work possible was not just the number of telescopes collaborating in the search, but their geographic distribution. The distance among the detectors — especially the 9,000-mi. north-south stretch from Spain to Antarctica — effectively means a collection dish nearly as big as the Earth itself. “More than five decades ago, this concept, called very long baseline interferometry, was developed,” said France Cordova, Director of the National Science Foundation, which coordinates the EHT. “This team took that concept to a global scale.” The collection of the data was completed in barely a week, but the collation and analysis of it took the better part of the past two years. The researchers from the different observatories divided into four teams and worked independently, sharing no information among themselves about preliminary results, lest they influence or contaminate one another’s data. Each team generated its own image of the M87 black hole from the data it had collected — and then they regrouped. “We brought everyone back together in April of 2018,” said Marrone. “We revealed to one another what we’d gotten, and we had four wonderfully similar pictures.” Integrating all of that imagery into the single picture that was revealed Wednesday presented a logistical challenge all by itself, since the teams had amassed five petabytes of data on half a ton of hard drives. No web-based system could handle all that, and instead, the data was transferred in a decidedly old-school way, with the hard drives physically flown to a Harvard lab, where the image integration was done. The true wonder of the of Wednesday’s big unveiling, of course, is not how the images were created, but what they will eventually reveal. For one thing, the mere fact that two black holes of such radically different scales were within reach of the EHT detectors will provide a much richer mix of data.<doc-sep>
It took eight telescopes and more than 200 astronomers to produce an astonishing, never-before-seen image of a distant black hole. Orange you glad you've just seen the first-ever image of a black hole? Today (April 10), a global collaboration of more than 200 astronomers presented the first image of a directly-observed black hole. The picture of a glowing orange-yellow ring around a dark core, was compiled from observations by eight ground-based radio telescopes known collectively as the Event Horizon Telescope (EHT). Researchers' data showed the black hole at the heart of Messier 87 (M87), a galaxy within the Virgo cluster located about 55 million light-years from Earth. But what exactly is the image showing, and why is the irregular ring orange? [IT'S HERE: The First-Ever Close-Up of a Black Hole] Though black holes are compact objects, they are exceptionally massive — the mass of M87's black hole is about 6.5 billion times that of our sun, the National Science Foundation (NSF) said in a statement. Because of this enormous mass, black holes warp spacetime, heating the dust and gas around them to extreme temperatures, according to NSF. By definition, black holes are invisible, because no light escapes from them. But a prediction made by Albert Einstein in his theory of general relativity stated that under certain circumstances, an outline of a black hole and its light-swallowing event horizon could be seen, according to representatives of the Haystack Observatory at MIT, which houses one of the EHT telescopes. "If immersed in a bright region, like a disc of glowing gas, we expect a black hole to create a dark region similar to a shadow," EHT Science Council chair Heino Falcke, a professor of radio astronomy and astroparticle physics at Radboud University in the Netherlands, said in the NSF statement. This is the first-ever image of a black hole. (Image credit: NSF) The black hole in M87 isn't the closest to Earth, but it's among the biggest, which made it a very promising target for the EHT, Derek Fox, an associate professor in the Department of Astronomy and Astrophysics at Penn State University, told Live Science (Fox was not affiliated with the EHT discovery). In the image, the dark circle represents the "shadow" of the black hole and its boundary, created by the glowing material that surrounds it. However, the colors of the bright ring in the image aren't the actual hues of the gas; rather, they represent a color map chosen by EHT researchers to depict the brightness of the emissions, Fox explained. "The yellow is the most intense emission, the red is less intense, and then black is little or no emission at all," Fox said. In the optical range, the ring around the black hole would likely appear white, perhaps tinged with blue or red, according to Fox. "I'd expect it to be more of a whitish glow that is brighter along the crescent, dimmer at the other points, and then black where the black hole is casting its shadow," he said. Originally published on Live Science.