Unfortunately for planet hunters, Mercury, Venus and Mars are all too close to the sun to observe; they will come out of the ...

While Io, the most volcanically active moon in the solar system, appears completely dry and devoid of water ice, its neighbor ...

Saturn reigns supreme when it comes to the number of moons orbiting any solar system planet. Including the 128 ...

On Saturday (Jan. 10), for example, we will see three satellites on one side of Jupiter (going outward from the planet: Ganymede, Io and Europa ), while the fourth ( Callisto) remains all by itself on ...