A shooting star ? which is actually not a star, but a meteor ? forms when the Earth runs into particles of dust and tiny space rocks. These bits of space junk burn up in the atmosphere, causing a blaze of light to streak across the sky.Continue Reading
The rocks and dust that form shooting stars usually come from asteroids and comets traveling through space, which shed the dust and rocks when they get too close to the sun or crash into each other. These pieces exist in space until the Earth, in its orbit, smashes into them or pulls them toward the planet via gravity.
The chunk of space debris itself is called a meteoroid, and it becomes a meteor when it plummets to the earth in a flash of light. Meteoroids are quite small, usually ranging from a speck of dust to a pea- or pebble-sized rock. They travel at an incredibly fast speed of 160,000 miles per hour, which is almost a hundred times faster than a bullet shot from a gun.
This speed causes friction between the meteor and the earth's air molecules, beginning the trail-of-light effect. Next, the heat of the outer atmosphere burns all the contents of the meteor in a fiery streak. Occasionally, a small chunk, called a meteorite, survives the heat and crashes to the earth's surface.Learn more about Comets & Asteroids