A rare “ultra-hot Neptune” has revealed startling details, from near-2,000°C surface temperatures to unexpected reflective ...

researchers have theorized that resting beneath Callisto's pockmarked surface is a liquid saltwater ... involving scanning Neptune's moon Triton to see if it has a subsurface ocean.

The study also suggests a similar makeup for Neptune. In essence, then, the surface of both planets are 5,000 mile-deep oceans, though it is a little more complicated than that. The Oceans Of ...