Europa: A little moon with a chance of life At last count, Jupiter has 95 moons, but the four main ones — Ganymede, Callisto, Io and Europa — were discovered in 1610 by famed Italian ...

July 25 has been a date marked by remarkable events that have shaped history.One of the most profound events occurred on July ...

Look east around 4 a.m. local time, just before dawn, to see the slender form of the crescent moon climb above the horizon.

ESA's Mars Express orbiter captured footage of the Mars' moon Deimos pass in front of Ganymede, Europa, Jupiter, Io and ...

NASA spotted something moving in one of the moons of Jupiter. Some natural satellites have similar structures to the Earth, ...

Retired NASA agent Joseph Gutheinz dismisses UFO claims, noting interstellar travel would take 70,000 years and suggesting military secrecy is behind many UFO sightings.

Even with a small telescope or binoculars, you can see the four largest moons of Jupiter: Io, Europa, Ganymede and Callisto.

However, the four largest moons – Io, Europa, Ganymede and Callisto – have been observed since 1610 and can be seen in backyard telescopes.

Since completing its primary science objectives in orbit of Jupiter, Juno has been conducting flybys of the Jovian moons Io, Europa, Ganymede, and Callisto.

Good binoculars may make it possible to see the planet’s four biggest moons — Io, Europa, Ganymede, Callisto. It reached opposition, its closest point to Earth, on Dec. 7 and appears as large ...

Credit: Astronomy: Roen Kelly Io, Europa, Ganymede, and Callisto orbit every two to 17 days. The innermost three moons are locked in a 1:2:4 resonance, so their relative positions repeat.