A black hole is when the massive matter is forced to fit into a small hole. Materials become packed tightly close together. This increases the gravitational field in the packed up materials. The gravitational pull is so strong that nothing can escape. Not even light can pass through because of the strength of the gravitational pull. The most things that lead to black holes are stars. When a star is dying, it will be squeezed into a small hole. Try picturing a star that is ten sizes or more the size of the sun being forced to fit into a hole with the diameter the size of New York City. The materials will be packed so closely so as to fit. This leads to the formation of a black hole. As this happens, materials are broken down and this to emission of light, X-rays, and other magnetic radiations. Scientists cannot, therefore, observe black holes by the use of a telescope. Black holes are therefore detected by observing their action on the surrounding objects. The best way you can tell of a black hole is when it passed above a cloud. Because of the immense gravitational pull, clouds will be pulled inwards in what we call accretion.
How big are black holes?
Black holes vary in size and can be big or small. The smallest black hole is the size of an atom. A black hole might be very tiny but with a very large mass. Remember that it is great mass sometimes the size of a very large mountain made to fit in a small hole. There are the largest black holes called the “super massive.” They are the largest and are believed to have masses that surpass that of a million suns put together. There I one super massive at the center of the Milky Way galaxy and is called the Sagittarius A. this black hole can fit in a ball of the size of a few million earth.
Can a black hole Destroy Earth?
The earth is not at any risk of falling into any black hole. This is because there are no any black holes close to the earth and the solar system. In case a black hole the size of the sun is formed in the solar system, the earth would not be any risk of falling into the hole. This is because the hole would have gravity equal to that of the sun and so the earth would orbit around the hole with other planets as they do with the sun today.