Every year, millions of rocky shards from space burn up in Earth's atmosphere, appearing as "shooting stars." How many survive high-speed landings?
Meteorites are space rocks that hit Earth. Huge impacts, like the one that probably wiped out the dinosaurs 66 million years ago, are rare.
Scientists think that less than 10,000 meteorites hit Earth's land or water each year. This is a drop in the bucket compared to the moon, which doesn't have an atmosphere.
Meteoroids are the small asteroids that usually become meteorites. They are the smallest objects in the solar system.
Bright meteors are called fireballs. Thousands of fireballs fly across Earth's sky every day, but most occur over oceans or in places with few people, and many are hidden by daylight.
Gonzalo Tancredi, an astronomer at the University of the Republic in Montevideo, Uruguay, said that most of the meteors seen on Earth come from meteor showers caused by comet dust.
Tancredi looked at data from the Meteoritical Society to figure out how many meteorites hit Earth each year.
From 2007 to 2018, there were 95 reports of meteorites hitting Earth, which is about 7.9 reports per year on average.
Tancredi thought that the total number of meteorites falling to Earth was about the same as the number of meteorites found in cities divided by the amount of land covered by cities.
Every six to ten years, 33-foot (10-m) space rocks may hit Earth's atmosphere, according to Tancredi. About once every 500 years, a rock big enough to cause an explosion like Tunguska in 1908 falls.