360Astronomers reveal the first picture of a black hole
On 10 April 2019, the Event Horizon Telescope team released the first image of a black hole: a glowing ring around a dark shadow at the centre of the galaxy M87, about 55 million light-years away. It is about 6.5 billion times the mass of the Sun. Eight radio observatories worked together as one Earth-sized telescope.
Black holes are regions where gravity is so strong that nothing, not even light, can escape. For a century they were studied through theory and their effects on nearby stars and gas, but no one had seen one.
To photograph one, astronomers needed a telescope the size of the Earth. The Event Horizon Telescope linked eight radio observatories, from Hawaii and Chile to Spain and the South Pole, using a technique that combines their signals.
In April 2017, the observatories pointed together at the centre of the galaxy Messier 87. The data was so large it was carried on hard drives, and it took two years to process.
On 10 April 2019, the team, of more than 200 scientists, revealed the image at news conferences around the world. It showed a bright, lopsided ring around a dark centre, matching the predictions of Einstein's theory of gravity.
In May 2022, the team released an image of Sagittarius A*, the black hole at the centre of our own galaxy.
- 1916
- Black holes are first predicted from Einstein's equations
- April 2017
- The observations of M87 are made
- 10 April 2019
- The first image is released
- May 2022
- The Milky Way's black hole is imaged
Sources: Event Horizon Telescope · European Southern Observatory · NASA.