The sky vault is a spectacular place. Although we still don’t know all the secrets of the universe, this mystery has kept humanity awake for many centuries, trying to figure out what happens up there. Perhaps, like many other lovers of the sky and astronomical observation, you have wondered what a meteorite is. This question leaves us with more doubts than answers. Fortunately for the curious, science has a clear explanation of what a meteorite is and how it is formed.
What is a meteorite?
On Earth, meteorites can be seen as dream lights, flashes that enchant our eyes as they cross the sky. And although many call them shooting stars, they are actually stellar dust and galactic matter that managed to pass through our atmosphere. But don’t worry, in most cases, they fail to cause harm to our planet or people.
To become considered as such, they first go through a process of evolution. In the first instance we have meteoroids, bodies of matter that revolve around our largest body, the sun, but that are too small to be considered within the range of planets, comets, or asteroids.
There are also meteoroids of different sizes, but when they are very small they are called micrometeoroids. And then when do they become meteorites? Here we will have to make an exact differentiation between one thing and the other.
We said that meteoroids are bodies of stellar dust and galactic mass that are hanging around in our solar system. When one of these bodies manages to pass through the Earth’s atmosphere, it produces an amazing flash of light that is called meteor (from the Greek meteorswhich means «phenomenon in the sky»).
In most cases, upon contact with the Earth’s atmosphere, the meteoroid produces a flash in the sky (a meteor) and then vaporizes into the air without actually touching the Earth’s surface. However, there are cases in which the latter does not occur, that is, the body of galactic material does not disintegrate in the air and ends up landing on Earth. This body is called meteorite.
How are they formed?
Meteoroids are almost always fragments of comets or asteroids., but they can also be rocks from satellites or planets that, due to large impacts, were thrown into outer space. Thus they end up wandering in the cosmos.
When a meteoroid becomes a meteorite, there is a change in its appearance. This is because upon impact with the atmosphere, the rock heats up and a phenomenon known as thermal ablation occurs, which causes wear on the rock. So eventually meteorites are sculpted by heat and that’s how we have evidence of galactic material in the form of precious rocks.
Why do they fall on Earth?
The arrival of meteorites on Earth is specifically determined by nothing. Factors such as its shape, speed, origin, composition, etc. intervene in the trajectory of a meteorite. Through its journey through the cosmos, each meteorite forms its line of travel and this is as unpredictable as the event that saw it born.
Scientists have calculated that about 17,000 space rocks streak across Earth’s skies each year. But most of these celestial bodies turn to dust before reaching the earth’s surface. It is a matter of luck and a good look to be able to capture the arrival of a precious rock from space, but we know that it is not impossible.
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