US Military's largest and most powerful heavy lift helicopter, the CH-53K King Stallion, is truly the king of the skies.

Four billion years ago, Ganymede literally got knocked sideways. A giant asteroid slammed into Jupiter’s largest moon, ...

Earlier this week, Saturn gained a whopping 128 new official moons, as the International Astronomical Union recognised ...

The vernal equinox occurs as Mercury stands still in Pisces and several of Jupiter’s moons transit in the sky this week.

The number of known moons in our Solar System has been rising for centuries, but astronomers say it has probably peaked – for ...

NASA announced that it has evidence that Jupiter’s moon Ganymede, the largest moon in our solar system, has a vast ocean lurking underneath its icy crust. WSJ's Monika Auger reports. Photo ...

A stunning Blood Moon March 13/14 caps off plenty of planetary action and sparkling stars in the sky this week.

Jupiter's largest moon Ganymede is generating "killer" waves of electrons that astronomers say could damage spacecraft going on future missions. These electromagnetic waves can be found all around ...

(Earth's Moon is 2,159 miles across, while Jupiter's largest moon, Ganymede, measures 3,270 miles.) They're also considered irregular, meaning their orbits are variably inclined, eccentric (oval ...

Ganymede, and Callisto. The Moon is non-luminous, meaning that it does not produce light. We see the Moon because it reflects light from the Sun, and half of the Moon’s surface is always ...