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.

Because Io is so close to its massive host planet, the moon is subjected to a tremendous gravitational pull as it orbits Jupiter once about every 42 hours, according to the Planetary Society. This at ...

Moon-quakes first measured by the Apollo astronauts have been attributed to these tides. The tides that Jupiter raises on Io, however are powerful enough to induce sufficient friction in that moon ...

Io is Jupiter's third-largest moon, spanning roughly 2,300 miles (3,700 kilometers) across, which makes it slightly bigger than Earth's moon. It orbits Jupiter at a distance of around 262,000 ...

NASA has used a tool that was never meant to be used to study other cosmic bodies, but the space agency used it to see the ...

Jupiter’s moon are also a huge point of interest for scientists, and Io is one of the most bizarre. Io is similar in size to Earth’s moon, but it’s a much more active place.

The volcano-laced surface of Jupiter's moon Io was captured in infrared by the Juno spacecraft’s Jovian Infrared Auroral Mapper (JIRAM) imager as it flew by at a distance of about 50,000 miles ...

Jupiter’s moon Io is a hotbed of geological activity, with over 400 active volcanoes. Because of this high level of activity, scientists have been debating for years about what’s going on ...

The Galileo spacecraft made its closest pass ever of Jupiter's moon Io on Monday, NASA's Jet Propulsion Laboratory said. Galileo came within 180 km of Io's surface as it passed over its south pole.

Because Io is so close to its massive host planet, the moon is subjected to a tremendous gravitational pull as it orbits Jupiter once about every 42 hours, according to the Planetary Society.