... Bright Meteor, Dark Sky . ... Two sulfurous eruptions are visible on Jupiter's volcanic moon Io in this color composite Galileo image. On the left, over Io's limb, a new bluish plume rises about 86 miles above the surface of a volcanic caldera known as Pillan Patera. ... Pictured: An Ancient Martian . ... Is this what an ancient Martian looked like? ... This bull's-eye pattern marks the impact of a mountain-sized comet or asteroid on the icy surface of Jupiter's moon Europa. ... Resolving Mira . ...