The supermassive black hole at the heart of our Milky Way galaxy has been photographed for the first time, giving astronomers invaluable insight into how black holes interact with their surroundings.
The object, known as Sagittarius A*, was captured by the Event Horizon Telescope Collaboration, the same global team that took the famous first-ever picture of a black hole inside the Messier 87 (M87) galaxy in 2019. Although the black hole itself is entirely dark, it’s encircled by a bright ring of glowing gas that’s being warped by its own gravity.
The picture was made possible by linking eight existing radio observatories across the globe to form a single “Earth-size” virtual telescope that collected data for many hours across multiple nights.
This new image might look very similar to the 2019 one of M87*, but the masses of the two black holes and the types of galaxies surrounding them are very different. The researchers were able to work out that Sagittarius A*, which sits at the center of our small spiral galaxy, consumes gas at a much slower rate than M87*, which resides at the center of a giant elliptical galaxy and ejects a powerful jet of plasma.
Despite being much closer to us, Sagittarius A* was significantly more difficult to capture than M87*. This is because the gas surrounding Sagittarius A* completes an orbit in just minutes compared with days to weeks for the gas orbiting the much larger M87*, causing the brightness and pattern of the gas to change rapidly. The team compared capturing it to “trying to take a clear picture of a puppy quickly chasing its tail.” To make the black hole visible, they developed sophisticated new tools to account for the gas movement.
“If Sagittarius A* were the size of a doughnut, M87* would be the size of the Allianz Arena, the Munich football stadium just a few kilometers from where we are today,” Sara Issaoun, NASA Einstein fellow at the Harvard & Smithsonian Center for Astrophysics, told a press conference at the European Southern Observatory in Germany.
“This similarity reveals to us a key aspect of black holes no matter their size or the environment they live in. Once you arrive at the edge of a black hole, gravity takes over.”
How SpaceX’s massive Starship rocket might unlock the solar system—and beyond
With the first orbital test launch of Starship on the horizon, scientists are dreaming about what it might make possible— from trips to Neptune to planetary defense.
Mapping the atmosphere on Mars can help advance science on our own planet
The Emirates Mars Mission is monitoring and measuring the climate and atmosphere of the red planet, but this effort also helps promote and advance science at a national level.
SpaceX just lost 40 satellites to a geomagnetic storm. There could be worse to come.
Increasing solar activity could play havoc with mega-constellations like Starlink in the coming years.
Space is all yours—for a hefty price
Commercial spaceflight is now officially a thing. But is it a transcendent opportunity for the masses, or just another way for rich people to show off?
Get the latest updates from
MIT Technology Review
Discover special offers, top stories, upcoming events, and more.