NASA's newest cosmic mystery involves a bizarre, never-before-seen planet that's more than eight times the size of Earth.

Strong infrared signals could reveal alien life on "waterworld" planets An artist's impression of a Hycean planet, where the new biosignatures could potentially be found Pablo Carlos Budassi ...

beginning the journey to reveal if this suspected waterworld might support life. With 95 moons, all with unique geology and features, the gas-giant planet Jupiter has the most satellites of any ...