The biggest moon in our solar system is Ganymede, which orbits Jupiter.

Here's a breakdown:

* Ganymede: Ganymede is larger than the planet Mercury! It's a fascinating moon with its own magnetic field and evidence of an underground ocean.

* Jupiter: Jupiter is the largest planet in our solar system.

It's easy to get confused, but remember: while Jupiter is the biggest planet, it's Ganymede that holds the title of the biggest moon.