While the movies and YouTube videos might have you believe that asteroids are heading straight toward Earth the European Space Agency, who monitor thousands of nearby stars, asteroids and comets, says it is highly unlikely that any sizable space object will hit earth during the next half-million years. The chance that a big star will move close enough to earth to cause damage is extremely small for the next 10 million years.
A comet consists mostly of ice. An asteroid is made of rock and metal. Crash some asteroids into each other and you get small pieces that break off, called meteoroids. When a meteoroid enters Earth’s atmosphere it leaves a visible streak of light and becomes known as a meteor. We generally refer to it as a falling star or shooting star.
When a meteoroid hits the ground on Earth it is known as a meteorite. About 500 small meteorites fall to earth every year but most fall in the sea and in unpopulated areas. They are small because meteoroids break up in Earth’s atmosphere – most are just vaporized before hitting land (or sea). A meteorite can be the size of a small rock but most are smaller than a pea.
The chances of being hit by a meteorite is very small. Animals are occasionally hit and there are many claims and reports of people being hit by a meteorite but most of those claims could not be verified. Which means that there is no record of a person being killed by a meteorite.