Dark, hungry, and inescapable: black holes are often portrayed as the ultimate cosmic villains. Yet, astronomers are on the brink of capturing a groundbreaking movie of a supermassive black hole in action, offering a new perspective on these enigmatic space entities. The Event Horizon Telescope (EHT) is set to track the massive black hole at the core of the Messier 87 galaxy throughout March and April, aiming to capture footage of the swirling disc at the event horizon, the boundary beyond which no light or matter can escape.
“The movie campaign is really revolutionary, not just because it’s technologically extremely challenging, but because it will accelerate our science by an order of magnitude,” said Sera Markoff, the newly appointed Plumian professor of astronomy and experimental philosophy at the University of Cambridge and a founding member of the EHT consortium. “We may be able to get a better handle on the speed that the black hole is rotating and the way black holes launch jets, both of which are major outstanding questions in our field.”
A New Understanding of Black Holes
Black holes have long been seen as “scary” objects, yet scientists increasingly recognize them as crucial to understanding the formation and evolution of galaxies in the early universe. “Black holes have a bad rap as these evil vacuum cleaners that just suck everything up,” Markoff noted. “To me, they represent the edge of our understanding of our universe, and they are endlessly fascinating. They actually play a very important role in the ecosystem of the universe.”
The EHT is a global network of 12 radio telescopes, spanning from Antarctica to Spain and Korea. In 2019, it unveiled the first image of a black hole’s shadow. This spring, as Earth rotates, M87’s central black hole will come into view for different telescopes, allowing a complete image to be captured every three days. The black hole’s immense scale—its mass equals 6 billion suns and it spans an area equivalent to the solar system—means it moves slowly enough for these snapshots to be stitched into a moving sequence.
Unraveling the Mysteries of Black Hole Dynamics
Understanding the black hole’s spin speed is crucial as it could help differentiate between theories on how these cosmic giants reach their massive sizes. If black holes grow mainly through accretion—steadily gathering material that strays nearby—they would likely spin at incredibly high speeds. Conversely, if they expand mostly through merging with other black holes, each merger could slow their rotation.
The observations could also shed light on how black hole jets are formed, which are among the largest and most powerful structures in galaxies. These jets channel vast columns of gas out of galaxies, slowing star formation and limiting galaxy growth, while creating dense pockets of material that trigger star formation bursts beyond the host galaxy. “M87 is launching these enormous jets that punch through the entire galaxy,” Markoff explained. “They can change the entire evolution of the galaxy and even surrounding galaxies.”
The Long Wait for Groundbreaking Results
While the movie campaign will take place in the spring, the sheer volume of data produced by the telescopes means scientists will have to wait for the Antarctic summer before the hard drives can be physically shipped to Germany and the US for processing. Thus, it may be a lengthy wait before the world sees the black hole in action.
Markoff, announced in December as the 17th Plumian professor, joins a prestigious lineage of astronomers, including Sir Arthur Eddington, Sir Fred Hoyle, and Lord Martin Rees. She hopes to leverage her position to inspire more individuals from under-represented backgrounds to pursue science. “I didn’t come from a scientific or academic family, so my interest in astrophysics really just came from reading science fiction and comic books,” she shared. “Given that I thought I would go to art school, it was quite an odd thing for me to be interested in, but these books exposed me to the ideas of black holes and instilled a desire to explore the universe. I was also lucky enough to have many supportive teachers, but I never seriously thought that I would be able to go into a career like this. Now I like to joke that I do sci-fi for a living.”
As the world eagerly awaits the results of this ambitious project, the potential insights into black hole dynamics and galaxy evolution promise to reshape our understanding of the universe.
