The Event Horizon Telescope (EHT) made history by capturing the first ever image of a black hole. It was described by scientists as “a monster” due to it being one of the heaviest known black holes. Located 500 million trillion kilometres away in a galaxy called M87 and measuring 40 billion kilometres across, it is three million times bigger than Earth and a whopping 6.5 billion times heavier than the Sun.
What does the photo mean?
The photo shows a perfectly circular dark hole surrounded by an extremely bright “ring of fire” that is brighter than all the other stars in that galaxy combined. This is why it can still be seen from Earth. The edge of the dark circle is the event horizon where the superheated gas (the halo) enters the black hole. The colours of the halo are not the actual hues of the gas but are instead colour representations of the brightness of the emissions. Yellow represents the most intense emissions, followed by red and black.
What is so special about this?
Black holes are dense objects with enormous masses which exert such strong gravitational pull that even light cannot escape. This theoretically means they should be invisible. This is why no single telescope is powerful enough to capture an image of it until now.
Therefore, EHT, a network of eight linked telescopes, was set up on high locations. The information captured (5000 terabytes) could not be transferred over the Internet due to its enormous size. Instead, they had to be stored on hundreds of hard drives which were then flown into central processing centres. The data was then processed by the algorithm developed by Katie Bouman and her team, who started creating it three years ago, and examined by four separate teams.
This revolutionary discovery further adds weight to Einstein’s general theory of relativity, enabling researchers to understand these mind-boggling black holes and answer the toughest questions about time and space.