i believe they are meteorites
sedimentary
-- meteoroids -- asteroids -- comets -- satellites -- planets (rocky ones)
Asteroids
You are on it.
It is called a meteorite.
A meteoroid.
Planet Asteroid Meteoroid
That, my friend would be a Comet.
A piece of space rock floating through space is a meteoroid. When it hits the atmosphere and glows white-hot with the heat of friction, it is a meteor.Once it hits the ground, it is a meteorite.
Since the Earth is rotating, and moving through space, and the rock is moving along with the Earth, then it does, but relative to the Earth, I'd say that the momentum of the rock (mass * velocity) is essentially zero.
Meteors
meteorite