What Is A Black Hole? A Closer Look At The Star Devouring Monsters

Astronomers unveiled the first photo of a black hole on Wednesday, putting to rest a lot of questions on one of the most mysterious things in the Universe.

Extremely powerful and massive, these star-devouring monsters are scattered across galaxies and has a gravitational field so strong that nothing, not even light, can escape. The strong gravity occurs because matter has been pressed into a tiny space. This compression can take place at the end of a star's life. Some black holes are a result of dying stars.

Black holes are invisible and come in a range of sizes. They cannot be seen because of the strong gravity that is pulling all of the light into the black hole's center.

The black hole's mass and size determine what kind it is. There are mainly three types of black holes.

The smallest ones are known as primordial black holes. Scientists believe this type of black hole is as small as a single atom but with the mass of a large mountain.

The most common type of medium-sized black holes is called "stellar." The mass of a stellar black hole can be up to 20 times greater than the mass of the sun and can fit inside a ball with a diameter of about 10 miles. Dozens of stellar mass black holes may exist within the Milky Way galaxy.

The largest black holes are called "supermassive." These black holes have masses greater than 1 million suns combined and would fit inside a ball with a diameter about the size of the solar system. Scientific evidence suggests that every large galaxy contains a supermassive black hole at its center.

Primordial black holes are thought to have formed in the early universe, soon after the big bang.

Stellar black holes form when the center of a very massive star collapses in upon itself. This collapse also causes a supernova, or an exploding star, that blasts part of the star into space.

Scientists think supermassive black holes formed at the same time as the galaxy they are in. The size of the supermassive black hole is related to the size and mass of the galaxy it is in.

The highly anticipated cosmic portrait of the black hole that was unveiled today belongs to the black hole at the center of Messier 87, the largest galaxy we know of, about 54 million light-years away.