Which objects in space are rock or metallic in composition?

Which objects in space are rock or metallic in composition?

• A. Asteroids
• B. Planets
• C. Stars
• D. Comets

Answer: (A)

Rocky or metallic bodies are solid and made from minerals and metals rather than ice or gas. Asteroids fit this description best: they are small, solid objects that orbit the Sun, mostly composed of rock and metal, and they linger in regions like the asteroid belt between Mars and Jupiter as leftovers from the solar system’s formation. Planets can be rocky too, but many are gas giants with thick atmospheres and little exposed rock, so not all planets match the idea of being rock or metallic throughout. Stars are not solid objects at all—they’re enormous spheres of plasma undergoing fusion. Comets do contain rock and dust, but their defining feature is a large ice component, so they’re not char­acteristically rock- or metal-rich like asteroids. Therefore, the object most consistently rock- or metallic in composition is the asteroid.

Rocky or metallic bodies are solid and made from minerals and metals rather than ice or gas. Asteroids fit this description best: they are small, solid objects that orbit the Sun, mostly composed of rock and metal, and they linger in regions like the asteroid belt between Mars and Jupiter as leftovers from the solar system’s formation. Planets can be rocky too, but many are gas giants with thick atmospheres and little exposed rock, so not all planets match the idea of being rock or metallic throughout. Stars are not solid objects at all—they’re enormous spheres of plasma undergoing fusion. Comets do contain rock and dust, but their defining feature is a large ice component, so they’re not char­acteristically rock- or metal-rich like asteroids. Therefore, the object most consistently rock- or metallic in composition is the asteroid.