A black hole is an area in space which has a very strong field of gravity and as a result, light is unable to escape from it. Due to this, black holes are invisible. In order to observe them, telescopes are equipped with special instruments which observe the behaviour of material and stars surrounding black holes in order to detect their presence. Black holes are formed when a large star dies and collapses into itself. It is this compression of matter into a tiny space, which causes the strong field of gravity.
A black hole in the Messier 87 galaxy rose to fame when it became the first black hole to ever be captured on an image. Because light is unable to escape from black holes, it has been very difficult to capture them in an image.
The Event Horizon telescope is a project which links eight ground based radio telescopes which shared data in order to create the first image of the black hole. This data was collated by a team led by MIT graduate Katie Bouman – who created the algorithm to help translate the data into images.