Meteors hit the Earth very frequently, but the impact frequency depends strongly on the size of the meteor:
- Small meteoroids, like dust and tiny particles, enter Earth's atmosphere daily, with about 100 tons of meteoric dust falling each day
- Meteors the size of sand grains and pebbles strike Earth numerous times per day but usually burn up completely in the atmosphere and do not reach the surface
- Meteoroids about 1 meter (3 feet) across hit Earth a few times per year
- Larger meteors around 10 meters (33 feet) in size enter Earth's atmosphere roughly every 6 to 10 years
- A meteor roughly 19 meters across, like the Chelyabinsk event in 2013, occurs approximately every 60 to 80 years
- Meteors about 50 meters (165 feet) in size, such as the Tunguska event in 1908, strike on average every 200 to 300 years
- Very large meteoroids, about 1 kilometer wide, impact Earth roughly every 300,000 to 500,000 years and can cause catastrophic global effects
- Extremely large impacts like the one that caused the dinosaur extinction (around 10 kilometers wide) happen on timescales of about 100 million years
In terms of meteorites (meteors that survive atmospheric entry and reach the ground), about 17,000 meteorites fall to Earth annually, though many are very small and go unnoticed
. Estimates suggest about 6,100 meteorite falls occur per year globally, with around 1,800 over land areas
. In summary, small meteors hit Earth constantly, but dangerous large impacts are very rare, occurring on timescales from centuries to millions of years depending on size. Most meteors burn up harmlessly in the atmosphere, and only a few cause significant damage every century or so
