Which planet's gravity induces tidal forces that cause volcanism on some of its moons and is orbited by the largest moon in the Solar System?

Which planet's gravity induces tidal forces that cause volcanism on some of its moons and is orbited by the largest moon in the Solar System?

• A. Mercury
• B. Jupiter
• C. Saturn
• D. Uranus

Answer: (B)

Tidal heating from a massive planet’s gravity can flex a moon enough to heat its interior, driving volcanism. Io, one of Jupiter’s moons, shows this clearly: Jupiter’s strong gravity repeatedly stretches and squeezes Io as it orbits, especially in resonance with Europa and Ganymede, causing internal melting and widespread volcanic activity. The clue about being orbited by the largest moon in the Solar System points to Jupiter, because its moon Ganymede holds that distinction. The other planets either don’t have the right combination—no moon that’s the Solar System’s largest orbiting them, or their moons don’t exhibit the same tidal-heating volcanism signature as Io. So Jupiter best fits both parts of the clue.

Tidal heating from a massive planet’s gravity can flex a moon enough to heat its interior, driving volcanism. Io, one of Jupiter’s moons, shows this clearly: Jupiter’s strong gravity repeatedly stretches and squeezes Io as it orbits, especially in resonance with Europa and Ganymede, causing internal melting and widespread volcanic activity.

The clue about being orbited by the largest moon in the Solar System points to Jupiter, because its moon Ganymede holds that distinction. The other planets either don’t have the right combination—no moon that’s the Solar System’s largest orbiting them, or their moons don’t exhibit the same tidal-heating volcanism signature as Io. So Jupiter best fits both parts of the clue.