What are shooting stars?

Shooting stars, or meteors, are mostly grit from space colliding at very high speed with air molecules high up in the sky.

As Earth travels in its orbit around the sun it runs into clouds of grit generally pulverized rock that also orbits the sun. Many shooting stars are produced by grit no larger than a grain of sand. Some of the more spectacular ones are pea-sized and the really stunning (but very rare) fireballs are the size of an orange or larger. These objects collide with air molecules some 60 miles (95 kilometers) above Earth's surface and, due to their very high speed, they begin to glow white hot. We see a streak of light as they burn up. The scientific name is meteor but shooting star will do fine.

As Earth slowly rotates, the side facing the direction of its orbit around the sun tends to run into more grit. This direction is directly overhead at dawn (at right angles to the sun) and this is why there tends to be at least twice as many shooting stars observable in the few hours before dawn, compared with just after sunset.

Occasionally a lump of rock survives the fiery journey and reaches the ground. These rocks are known as meteorites. They tell us a lot about the composition of the solar system.