What is the definition of a meteor?

The definition of a meteor specifically refers to the phenomenon that occurs when a small rock or particle from space, known as a meteoroid, enters the Earth's atmosphere and produces a bright streak of light as it burns up due to friction with the air. This bright streak is what we commonly call a "meteor."

While a meteoroid can potentially survive its journey through the atmosphere and reach the Earth's surface, in everyday language, "meteor" typically describes the event of seeing this streak of light in the sky, not necessarily what survives to hit the Earth. Therefore, the precise definition aligns with the characteristics of the event occurring in the atmosphere, where only a small fraction of meteoroids that enter as meteors actually become meteorites upon reaching the ground.

The other definitions provided do not accurately describe a meteor. A celestial body that orbits the sun is better characterized as an asteroid or planet, a piece of rock that floats in space could refer to many objects but not the phenomenon of a meteor itself, and a light phenomenon caused by the movement of stars does not relate to meteors, as this does not involve the entry of objects into the Earth's atmosphere.