Cadet Competition Written Practice Exam

What are chunks of rock ranging from dust particles to a few hundred miles across called?

1. Comets

2. Meteoroids

3. Asteroids

4. Planetesimals

The correct answer is: Asteroids

The term for chunks of rock that range from tiny dust particles to objects that can be a few hundred miles across is specifically "asteroids." Asteroids are primarily found in the asteroid belt, located between the orbits of Mars and Jupiter. They are remnants from the early solar system, composed mostly of rock and metal, and are typically larger than meteoroids, which are smaller particles. While comets are also celestial bodies, they are composed largely of ice, dust, and rocky material, which distinguishes them from the rocky composition of asteroids. Meteoroids refer to smaller fragments that can range from grains of dust to about a meter in diameter but do not typically reach the size of hundreds of miles across. Planetesimals, on the other hand, are larger bodies that can form planets, suggesting they are more massive than asteroids and involved in the early stages of planet formation. Overall, when considering the size range from dust to hundreds of miles across, "asteroids" is the most accurate term, which is why this is the correct answer.