what are black holes?

Introduction

     Usually in shows they have black holes in an episode or two. But have you ever wondered what black holes actually are, and what they do? Well, this is for you. Find out the facts about black holes

All of the sizes

     You might think all black holes are the same exact size, but there are really four different sizes: Supermassive, Stellar, Intermediate, and Miniature

     The supermassive black hole is about the size of 10 billion suns! And the miniature black holes are about the size of an atom (0.1 nanometers). Most scientists believe the miniature black holes were created when the universe first started, and merged to bigger black holes. If the center of a very large star collapses, a miniature black hole is created.

How do scientists see black holes?

     Black holes are invisible because a powerful gravity sucks the light into the center of the black hole. This light is impossible to see with human eyes. If a black hole and a star are near each other, a powerful light is created. Scientists use special tools such as telescopes or satellites to see this powerful kind of light. 

Why do black holes pull?

     Gravity is a force that pulls. The bigger an object is, the more pulling force it has. The biggest object near you right now is Planet Earth, so that is why you are not floating in the air because you are being pulled by the force of gravity toward the Earth.

   The sun is a star. It is a million times bigger than the Earth, so it has a much larger force of gravity than the Earth.

    If a star has collapsed into a black hole, that star has tons and tons of gravity, so that is exactly why black holes pull so strongly.

The scientists behind black holes

 Back in 1967, an American scientist named John Archibald Wheeler chose the name “Black Hole” because he thought it would be perfect for something very dark and deadly. Scientists like him all around the world have tons of questions about black holes, and they are even still researching them.

     Did you know that the first black hole that scientists ever found was named Cygnus - X1? It was found in the 1960’s and the mass of Cygnus-X1 is about 15 times bigger than our sun.

    The sun has a mass of 4.4 x 1030 pounds. That means 4,400,000,000,000,000,000,000,000,000,000 pounds. Cygnus X-1 is about 15 more massive, so Cygnus X-1 is HUGE! 

CAN A BLACK HOLE EAT A BLACK HOLE?

     It is possible for one black hole to eat another black hole. Because of this, supermassive black holes were created by merging smaller black holes. 

    For example, you might have played a game where you merge things to make them bigger. Well, black holes are almost the same. What black holes do is get bigger and bigger in size by merging. That's why we have supermassive black holes, when the force of one black hole pulls in another black hole.

Can black holes hurt you?

      Our Earth and our solar system are not in danger of being destroyed by a black hole. This is because they are way too far in space to hurt you. The nearest black hole called Sagittarius A* is more than 1,000 light years away from the Earth. 

     Light travels at a speed of 186,000 miles per second. A light year is the distance light travels in one year. So 1,000 light years is very, very, VERY FAR AWAY! 

     Black holes don't just zoom around space swallowing up planets and moons and stars. There is no chance they would just randomly go around earth eating people and buildings. So because the solar system is so far away from the nearest black hole, Earth is not going to be suddenly pulled into a black hole.

Conclusion

    There are many many other questions, possibilities, and beliefs about black holes. And there are many mysteries that scientists haven't even researched yet. Because black holes are so far away and so mysterious, we are always trying to discover more about them. But maybe you’ll become a black hole scientist one day, and ask tons and tons of questions to solve the mysteries.

Telescopes around the world, including the ALMA telescope shown above in Chile, joined forces to create the Event Horizon Telescope. This enabled people to capture the first images of a black hole.

This artist's image of the black hole named Cygnus X-1 was the first black hole ever to be discovered in 1964.

John Archibald Wheeler gave black holes their name back in 1968.

This black hole is named Saggitaruis A* and was found in 1974. It is the closest black hole to our solar system.

If you ever thought one black hole can eat another black hole, they can. But they actually merge into each other, getting bigger and bigger in size.

This is an artist's image of "spaghettification" caused by a black hole.

This simulation imagines two black holes spinning and merging into one.

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