The Galileo Spacecraft Measured That the Moon Ganymede Had a Magnetic

question 30

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