The first direct image of the M87 Galaxy’s supermassive black hole that’s almost the size of our solar system required telescopes of unprecedented precision and sensitivity to give the human species a look into the unknown. The realization of this telescope – the Event Horizon Telescope – was a formidable challenge which required upgrading and connecting a planet-scale network of eight pre-existing telescopes deployed at a variety of challenging high-altitude sites, including volcanoes in Hawaii and Mexico, mountains in Arizona and the Spanish Sierra Nevada, the Chilean Atacama Desert, and Antarctica.
We gave humanity its first view of a black hole — “a one-way door out of our universe,” said EHT project director Sheperd S. Doeleman of the Center for Astrophysics, of the image of the massive black hole at the center of elliptical galaxy M87 as it was 55 million years ago “This is a landmark in astronomy, an unprecedented scientific feat accomplished by a team of more than 200 researchers.”
“The gates of hell, the end of space and time.” That was how black holes were described at the press conference in Brussels where the first ever photograph of one was revealed. The black hole, a super-massive object at the center of M87 shown above, really is a monster, observed Ellie Mae O’Hagan for The Guardian. “Everything unfortunate enough to get too close to it falls in and never emerges again, including light itself. It’s the point at which every physical law of the known universe collapses. Perhaps it is the closest thing there is to hell: it is an abyss, a moment of oblivion.”
Astrophysicist Janna Levin author of “Black Hole Blues” with Columbia University notes for The Guardian that we are actually seeing the black hole as it was 55 million years ago, because it’s so far away the light takes that long to reach us. “Over those eons, we emerged on Earth along with our myths, differentiated cultures, ideologies, languages and varied beliefs,” she says. “Looking at M87, I am reminded that scientific discoveries transcend those differences.”
The Black Hole Cam (BHC) Team was led by astrophysicists from Goethe University in Frankfurt, the Max-Planck Institute for Radio Astronomy (MPIfR) in Bonn and the Radboud University in Nijmegen, the Netherlands.
“After decades of research where we could postulate black holes only indirectly, albeit with great precision, it was not until LIGO in 2015 that we were able to make the impact of merging black holes on space-time ‘audible,’” explained Michael Kramer, Director at MPIfR and co-PI of the ERC Black Hole Cam project. “Now we can finally ‘see’ them, and investigate the extreme warping of spacetime they are causing in a unique way.”
Next Up a Space-Based Radio Telescope in Orbit Around the Earth
The EHT observations use a technique called very-long-baseline interferometry (VLBI) which synchronizes telescope facilities around the world and exploits the rotation of our planet to form one huge, Earth-size telescope observing at a wavelength of 1.3mm. VLBI allows the EHT to achieve an angular resolution of 20 micro-arcseconds — enough to read a newspaper in New York from a sidewalk café in Berlin.
“The 30-m IRAM telescope on Pico Valeta in the Spanish Sierra Nevada is the most sensitive single-dish telescope within the EHT network,” explained Karl Schuster, director of IRAM and member of the EHT board. “Bringing together the best radio telescopes on four continents we can reach an unprecedented sensitivity and spatial resolution, allowing scientists to carry out measurements at the very limit of what is physically possible.” The second IRAM telescope, NOEMA in the French Alps, joined the EHT network in September 2018.
“Imagine if we can make a movie of a black hole instead of a still image,” Doeleman said in an EHT talk at the South by Southwest (SXSW) festival in Austin, Texas. “We want to make a movie in real time of things orbiting around the black hole. That’s what we want to do over the next decade.
Over the longer haul, the EHT collaboration would like the virtual scope to include an off-planet dish. “World domination is not enough for us; we also want to go into space,” Doeleman said. “If we could put a space-based radio telescope in orbit around the Earth, it would sweep out even more of that virtual mirror and do it much more quickly.”
The image at the top of the page shows a smattering of orange stars against the black backdrop of space with a small black circle in the middle and a rectangle identifying the location of the M87 black hole.
The Daily Galaxy, Max Goldberg, via Goethe University Frankfurt