The predawn hours of Aug. 8 present a perfect opportunity to see Jupiter's four largest moons line up next to the "King of the Planets" as it voyages through the stars of the constellation Gemini.

Looking for a sky event this week? Check out our full Sky This Week column. January 20: Comet Schaumasse slides by some ...

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

Sky This Week is brought to you in part by Celestron. Friday, January 9Mars is in conjunction with the Sun at 7 A.M. EST, ...

In a landmark observation by a team of international researchers, NASA's Juno spacecraft has, for the first time, clearly detected the auroras of Jupiter's moon Callisto. This discovery completes the ...

Research into Jupiter’s moons shows Io and Europa did not evolve apart but formed with opposite compositions from the ...

Volcanic eruptions are difficult to predict, but observations have shown the largest and most powerful volcano on Io, a large moon of Jupiter, has been erupting on a relatively regular schedule.

On January 7, 1610, the Italian astronomer Galileo discovered three of Jupiter's moons: Callisto, Europa and Io. When he looked at Jupiter through his telescope, he saw what he thought were three tiny ...

With the moon out of the way on Jan. 18, bright Jupiter and Saturn become stand-outs in the January night sky.

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