Sejal, age 7, Bangalore, India The planet Jupiter has no solid ground – no surface, like the grass or dirt you tread here on Earth. There’s nothing to walk on, and no place to land a spaceship.

How many moons does Jupiter have? Scientists have discovered dozens of them, but the answer may be more complicated than it ...

Ever since the Galileo spacecraft flew by Jupiter's icy moons in 1989, scientists interested in life beyond our planet have been ... with Jupiter in the background. Pic: NASA/JPL-Caltech via ...