Each year, millions of pieces of rock from space burn up in Earth’s atmosphere, many of which briefly glow and appear as “shooting stars” in the sky. So, how many of them manage to break through this obstacle and crash into the Earth’s surface?
Rocks that manage to descend from space to the Earth’s surface without breaking apart are called meteorites. Massive impacts, such as those caused by an asteroid or comet about 10 kilometers in diameter that ended the dinosaurs’ reign some 66 million years ago, are extraordinarily rare. Instead, most of the rocks that fall to Earth are very small, and very few pass through Earth’s atmosphere unburned.
Scientists have calculated how many meteorites hit Earth’s land or water each year. These impacts are usually caused by small asteroids, the smallest members of the Solar System. They are less than 1 meter in size, most of them the size of a grain of dust. Some may be moons or fragments from planets. For example, according to the report of the American Meteor Society, there are 300 known meteorites from Mars that have fallen to Earth so far.
When meteorites enter the Earth’s atmosphere, they burn due to air friction, and during this combustion, thin flame lines are seen in the sky. We call this a shooting star. Most meteorites that fall to Earth fall in uninhabited places or in the oceans, and many are not visible in the sky because they fall in daylight.
Scientists analyzed the collected data to estimate how many meteorites successfully hit Earth each year. According to calculations, about 6,100 meteorites fall each year, and about 1,800 of them crash into land. In addition, it has been calculated that there is a probability of a meteorite larger than 10 meters in size falling to Earth every ten years. There’s a chance that a catastrophic meteorite-sized impact on Tunguska in 1908 would occur every 500 years. The probability of a 1 kilometer wide meteorite falling was calculated as once every 300,000 to 500,000 years.
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