The US National Aeronautics and Space Administration (NASA) has released an animated video showing the size of supermassive black holes compared to the Sun and the Solar System. All the black holes seen in the video are real։ scientists have quite a lot of information about them, including their size.

A black hole is a region of spacetime where gravity is so strong that nothing, including light or other electromagnetic waves, has enough energy to escape its event horizon. Most black holes have masses of about 100,000 times the size of the Sun or more.

The video first shows the Sun, and in comparison, the supermassive black hole in the dwarf galaxy named J1601+3113. It is only slightly larger than the Sun, but has a mass many times that of the Sun. The radius of the event horizon (Schwartzschild radius) of J1601+3113 is slightly smaller than the radius of the Sun. But due to its shadow around the event horizon, J1601+3113 appears twice the size of the Sun. If the Sun were a black hole, its Schwarzschild radius would be only 2.95 km, and the diameter of the Sun's event horizon would be about 6 km.

The video next shows the supermassive black hole at the center of one of our closest galaxies, Circulus. The size of this object, together with the shadow, is comparable to the radius of the orbit of Mercury, and its mass exceeds 4 million times the mass of the Sun.

The largest object in the video is the supermassive black hole TON-618, which has a mass 66 billion times that of the Sun. It is more than 10 billion light years away from us.

Interestingly, theoretically, a supermassive black hole cannot be larger than 50 billion solar masses, and that is why the TON-618 object is considered very, very unique in this regard.

Recently astronomers discovered the largest black hole known to date. Its mass is 32.7 billion times greater than the mass of the Sun. It is located in the center of one of the galaxies in the Abell 1201 cluster, which is located 2.7 billion light years from Earth. This black hole was not shown in the video.