Assume that we discover a new moon of Jupiter. It orbits Jupiter at a large distance and in the opposite direction that Jupiter rotates. It is much smaller than most of Jupiter's other moons and has a density close to that of Earth rocks. Therefore, this moon is most likely:
A) a regular moon that formed with Jupiter in the early solar system
B) an irregular moon that is most likely a captured asteroid
C) an irregular moon that is most likely a captured comet
D) an irregular moon that is most likely a protoplanet which collided with Jupiter in the early solar system and then was caught in orbit by Jupiter's gravity
E) more information is needed before any conclusion can be made

Question

Quizplus · Accepted Answer

The moon's orbit in the opposite direction of Jupiter's rotation suggests that it was not formed with Jupiter in the early solar system. Additionally, its small size and density suggest that it is not a regular moon. The fact that it is in a distant orbit and is likely a captured object further supports the idea that it is an irregular moon, which are typically captured asteroids. Captured comets would have lower densities, and the protoplanet explanation would require more information to be confirmed. Therefore, B is the best choice.

Assume That We Discover a New Moon of Jupiter