Largest local moon home to salty sea
Ganymede is the largest moon in the solar system, orbiting the largest planet, Jupiter. It’s been the subject of interest for decades as the possible home of a salty ocean. It’s now been confirmed, even though it’s not visible on the surface of the moon, which is covered in miles of ice.
Since we haven’t been looking under that ice, we’ve been gathering evidence of that ocean less directly. Thankfully, Ganymede has a magnetic field similar to Earth, with a north and south pole. And now the Hubble Telescope has helped us detect that that field is moving in a pattern that would be consistent with the presence of a salty ocean.
Naturally, with water’s role in life as we know it, discovering another body of water warm enough to remain a liquid in our solar system is pretty exciting.
Source: Moon River? No, It's An Ocean On One Of Jupiter's Moons! by Nell Greenfieldboyce, The Two-Way