The Galileo Spacecraft Measured That the Moon Ganymede Had a Magnetic

Multiple Choice

The Galileo spacecraft measured that the moon Ganymede had a magnetic field, indicating that its interior was at least partly melted and warm. What do scientists think is the most likely reason for this?

A) Ganymede is so far away from Jupiter, it is an independent world, and can compress its core without interference
B) Ganymede has thousands of volcanoes, which then send material downward to heat up its interior
C) Ganymede is a relatively small moon, and therefore much easier to heat up than its neighbor moons
D) Ganymede is heated by tidal forces from Jupiter
E) Scientists have no idea what causes the inner part of Ganymede to be warm; this is an unsolved mystery