The things that fall are actually quite small stones, or pebbles, or balls of iron and other elements. They sometimes fall all the way to the Earth and can be picked up afterward. By far the greatest number of them, however, never reaches the surface of the Earth as stones or meteorites at all, for they are burnt or broken up into dust by the Earth’s thick atmosphere. A very great amount of dust in the air, especially in the higher levels of the atmosphere, is made of this meteoric dust.
We see only a few of the falling stars that are caught by the Earth’s atmosphere. Though they are falling all the time we never see those that fall in the daytime. They become bright and hot as they pass through the air, but not bright enough for our eyes to notice when the Sun is shining upon our part of the Earth. Quite a lot of the present matter of the Earth has been derived from meteors or falling stars in this way. The meteoric dust can sometimes be found lying on the snow of the high peaks of mountains.