Asterorides, comets and meteorites are the smallest members of the Solar System. Some cross the Earth's orbit. It is estimated that there is a great impact every 100,000 years.
The asteroids they are rocky bodies that did not come together to form planets. The main ring of asteroids is between the orbits of Mars and Jupiter. Another group, the Trojan asteroids, share orbit with Jupiter.
Some, such as the Apollo asteroid group, cross Earth's orbit. Billions of years ago, huge asteroids bombarded our planet. It is possible that the impact of one of them against the Earth formed the Moon. In each collision, the asteroids split into smaller pieces. That is why today there are more asteroids, although they are much smaller. It is difficult for a large asteroid to crash against Earth.
The kites They come from the outskirts of the Solar System, the Kuiper Belt and the Oort Cloud. Its core is of ice and, when approaching the Sun, a tail of gas and dust forms behind. Some have periodic orbits, and sometimes they cross those of the planets. Others only visit us once, and their orbits are unknown. Jupiter's gravity deflects many, but others enter into the inner Solar System.
Each time a comet passes near the Sun it becomes smaller, and eventually wears out. This reduces the chances of a great impact. In the past, comet impacts released large amounts of carbon, hydrogen, oxygen and nitrogen into the atmosphere, the essential elements for life. Are we also children of comets?
The meteorites they are remains of kite tails or small asteroids. Millions of meteors enter the atmosphere every year. But they are not large enough to produce a great impact. Most disintegrate before reaching the ground. When a meteor reaches the ground it is called meteorite. It is believed that a large meteorite caused the extinction of dinosaurs 65 million years ago. The largest meteorite in the world that is preserved is in Greenland and weighs more than 600 tons.
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