A meteor is the light phenomenon, known popularly as a shooting star or falling star, that results from the entry into Earth's atmosphere of a solid particle, or meteoroid, from space. Meteors occur at an altitudes of about 100 kilometers (60 miles). The typical meteor lasts for a few tenths of a second to a second or two, depending on the meteoroid's entry speed, which can vary from about 11 to 70 kilometers per second (7 to 45 miles per second).
A few meteors per hour may be seen on any clear, moonless night at any time of the year. But at certain times of the year there are meteor showers, which occur when the Earth passes through dust particles spread around the orbit of a comet. Most of the meteors appearing during the year are sporadic meteors, not associated with cometary orbits.
A meteor train is a trail of ionized dust and gas that remains along the path of a meteor. A persistent train is one that remains visible for more than a second.