Event Horizon Telescope

 An event horizon telescope is a group of telescopes working together on an international level to catch an image of the event horizon of a black hole. A black hole is the darkest thing in space and we cannot see it even with a telescope because light cannot escape the gravity of a black hole. So how to study a black hole! 

It was a theoretical study the some of the light can bend at the event horizon of a black hole. The amount of light is less and cannot be see-through normal telescopes. So we needed to build a very powerful telescope, about the size of the earth, which is impossible.

Artistic image of an event horizon of a black hole

      Black holes have unimaginably high density and therefore gravity is very strong. The event horizon is a space around the black hole inside which we cannot see anything, inside which light have no chance to escape from the gravity of a black hole. and if gravity won't come out, we cannot see anything from that part. All we can see is the boundary of the limit of vision called the event horizon. 

      The basics of telescopes are simple. Bigger the telescope larger the resolving power. And if the resolving power is high we can see smaller objects from space. Black holes are dead stars and they are very small in size also the amount of light coming from the horizon is small so we need a larger telescope.

     

List of an array of telescopes working together as an EHT

    

    Making a large telescope has a limit. Economical and physical are both types of limits and if we overcome them, it is almost impossible to make a telescope of the size of the earth. The scientists made it possible. They used many telescopes together to look into space at one point. Telescopes work synchronously. Collected data is processed on the Supercomputer. These telescopes collect vast amounts of data. 64 Gb/second data gets collected by each telescope in the array. and a supercomputer is needed to process the data. This telescope receives radio waves.
    The idea of EHT (Event horizon telescope) was unique and successful and in 2019 EHT released its first image of a black hole.

The very first image of a black hole

After this EHT released many more but the image of a black hole was a very important achievement of EHT. In the history of telescopes, EHT is the largest telescope humans have ever built.