Terminal velocity
Terminal velocity is the steady top speed an object reaches when air resistance balances its weight as it falls.
Anything falling through air speeds up until the push of air resistance equals the pull of gravity. After that it stops accelerating and falls at a steady speed called its terminal velocity. A skydiver reaches it, and so does a meteorite.
This matters because meteorites do not hit the ground at their cosmic speeds. Air slows them dramatically during flight, and in dark flight they simply fall at terminal velocity. For a stone of a few hundred grams to a few kilograms, that is typically somewhere around 100 to 300 kilometres per hour, depending on its size, shape and the thickness of the air. That is fast enough to dent metal or bury itself in soft soil, but not fast enough to make a crater. In 1954 a stone of about 4 kilograms crashed through a roof in Sylacauga, Alabama, bounced off a radio and bruised a woman resting on her sofa.
Only very large meteoroids, many tonnes or more, keep enough of their original speed to blast out an impact crater.
Related terms
Level: Explorer Ages 10 and up