What are Black Holes?
Black holes are one of the strangest objects in the universe. A black hole is where gravity has become extremely strong; nothing around the black hole can escape, not even light. They are at the center of most galaxies, including the Milky Way. Black holes are very heavy and can have the mass of several million suns. They don't live forever, but slowly evaporate by returning their energy to the universe. The mass of a black hole resides in its center . Black holes are only different from each other in regards to their mass and the way they spin. NASA thinks that there could be more than a billion black holes in space.
Are They Visible?
Black holes are actually invisible. We can't see them because they do not reflect light. The only way that scientists know they exist is by observing the light and the way they affect nearby dust, stars and galaxies. Many of them are surrounded by discs of material and as these discs swirl, they become extremely hot and give off X-rays.
How are They Formed?
Almost all black holes are born when a giant star runs out of energy. The star explodes, and its center collapses because of its own weight. The result of this is an explosion called a supernova. If the star has enough mass, it will collapse on itself down to a very small size. Due to its small size and enormous mass, the gravity will be so strong it will absorb light and become a black hole. Black holes can grow incredibly huge as they continue to absorb light and mass around them. They can even absorb other stars.
Who Discovered Black holes?
John Michell and Pierre-Simon Laplace both brought up the idea of black holes in the eighteenth century. In 1967, John Archibald Wheeler coined the term "black hole."
Written by: Maysa Nashawati
Works cited:
“Astronomy for Kids.” Ducksters, www.ducksters.com/science/black_hole.php.
“Black Holes.” ESA - European Space Agency, www.esa.int/kids/en/learn/Our_Universe/Story_of_the_Universe/Black_Holes.
“Black Holes.” National Geographic Kids, National Geographic , 10 Feb. 2021, kids.nationalgeographic.com/space/article/black-holes.
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