A meteor is the bright streak of light you see flashing across the night sky when a small piece of space rock burns up in Earth's atmosphere. People often call them “shooting stars,” though they're not stars at all.

Here's what happens: tiny rocks or particles of dust are constantly zooming through space, and when Earth's orbit crosses their path, they slam into our atmosphere at tremendous speeds, sometimes 40,000 miles per hour or faster. The friction with air molecules heats them so intensely that they vaporize in a brilliant flash, creating that streak of light you might spot on a clear night.

Most meteors come from debris left behind by comets or from fragments of asteroids. The rock itself, while still in space, is called a meteoroid. Once it enters our atmosphere and lights up, it becomes a meteor. If any piece survives the burning journey and actually hits the ground, that chunk of space rock is called a meteorite.

During a meteor shower, Earth passes through a particularly dense trail of space debris, and you might see dozens of meteors per hour, all appearing to radiate from the same point in the sky. Some famous meteor showers, like the Perseids in August, happen at the same time every year, giving stargazers a reliable show.