Looking for a sky event this week? Check out our full Sky This Week column. October 12: The Saturn Nebula shines Last Quarter ...

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.

Callisto's shadow will follow along Jupiter's south-south temperate belt from 9:09 p.m. to 12:54 a.m. tonight Feb. 22-23, 2014. A smaller telescope magnifying around 60x or higher will show it. Credit ...

Firing off a string of action snapshots like a sports photographer at a NASCAR race, NASA’s Hubble Space Telescope captured the rare occurrence of three of Jupiter’s largest moons racing across the ...

The moon, just hours past its last quarter phase, will rise above the east-northeastern horizon shortly before midnight local ...