Dave Rider, age 13, of Lansing, Michigan,for his question:

How hard does a meteor hit the ground?

Every day, hundreds of pebble sized meteorites plonk on the ground and splash into the sea. This type lands with a slight thud, somewhat like a ripe apple falling from a tree. By the time you find it, is almost certain to be cool enough to handle. Most meteors are granules that are consumed to ashes high in the atmosphere. Their blowing dust takes a long time to filter lightly down to the ground. On rare occasions, we are bashed by a meteorite as big as an asteroid. It lands with the force of a falling mountain, gouging a huge crater in the ground. The thundering roar is heard for miles around.

These variations seem odd because gravity pulls everything down at the same rate. However, the speed of falling meteors is modified by the air, by their sloping paths and other factors. These anti gravity factors let down meteoric dust lightly and delay the falling speeds of medium sized meteors. The crash landing usually shatters chondrites and many soft, stony meteorites. But the crash is not severe enough to break pebble sized meteorites made of iron and hard metals.