What is a meteor?

• A. A meteoroid in space
• B. Meteoroids burning up in atmosphere
• C. A meteoroid entering Earth's atmosphere and burning up
• D. A rock that has landed on Earth

Answer: (C)

A meteor is the bright streak you see in the sky when a meteoroid enters Earth's atmosphere and burns up from the intense heating due to air friction. Think of a meteoroid as a small rock in space; once it hits the atmosphere, the friction makes it glow and often break apart, creating that visible light. If any piece makes it to the ground, that fragment is a meteorite. So the description that fits best is a meteoroid entering Earth's atmosphere and burning up. The other ideas miss the exact moment or result: a meteoroid in space isn’t yet a meteor, burning up in the atmosphere without specifying entry misses the key step, and a rock that lands on Earth is a meteorite, not a meteor.