What is a meteoroid?

A meteoroid is defined as a small piece of dust or rock that orbits the Sun. This classification typically includes objects that are smaller than asteroids and can be remnants from comets or asteroids. Meteoroids can vary in size, from tiny grains to objects as large as several meters. When these objects enter the Earth's atmosphere and heat up due to friction, they become meteors, and if they survive the journey and land on Earth, they are referred to as meteorites.

The other options, while related to celestial objects, do not accurately define a meteoroid. For instance, defining a meteoroid as a large meteor that crashes into Earth would be incorrect because meteoroids are smaller precursors to meteors. Similarly, describing it as a remnant of a comet that has disintegrated is too specific and misses the broader definition that includes various origins. As for a planet that has stopped orbiting, this represents a completely different category of cosmic objects, unrelated to the concept of meteoroids.