Question

*meteoroids are in space; meteors are burning up in earths atmosphere; meteorites have landed on the surface of a planet or moon. an object is mostly made of ice and rock. it is approximately 500 kilometers in diameter. it likely has an ocean of liquid water beneath its snow - covered crust. it has active volcanoes that emit water vapor into space. it orbits a planet. which image shows the object described above? images: enceladus, a moon; vesta, an asteroid; 103p/hartley, a comet

Explanation:

Step1: Analyze the object's description

The object is made of ice and rock, ~500 km in diameter, has an ocean under snow - crust, active volcanoes emitting water vapor, and orbits a planet.

Step2: Evaluate each option

• Enceladus (a moon): Moons orbit planets. Enceladus is a moon of Saturn, has ice - rock composition, subsurface ocean, and active geysers (volcano - like) emitting water vapor. Its diameter is around 500 km.
• Vesta (asteroid): Asteroids are mostly rocky, don't have subsurface oceans or water - vapor - emitting volcanoes as described, and orbit the Sun (not a planet directly in the same way a moon orbits a planet).
• 103P/Hartley (comet): Comets orbit the Sun, are made of ice but have a different structure and orbit pattern, and don't orbit a planet.

Answer:

Enceladus, a moon