New Horizons Discovers Methane 'Snow' on Pluto's Mountain Peaks

Methane “snow” on mountain peaks in the Cthulhu region of Pluto. The enhanced color version of the inset image is on the left and the false color version is on the right. The image covers an area 280 miles (450 kilometers) long by 140 miles (225 kilometers) wide. Image Credit: NASA/JHUAPL/SwRI

As the data […]

New Horizons Finds Evidence for Frozen Ocean Inside Pluto's Moon Charon

The canyons of Charon, some of which dwarf the Grand Canyon on Earth. Image Credit: NASA/JHUAPL/SwRI

One of the most surprising discoveries in recent years in the outer Solar System is that there are small moons which have oceans inside them. Jupiter’s moon Europa and Saturn’s moon Enceladus are now known to have global […]

Cassini Prepares for Last Epic Flyby of Saturn's Ocean Moon Enceladus

Cassini’s final close flyby of Enceladus will be on Dec. 19, 2015. Image Credit: NASA/JPL-Caltech

The Cassini spacecraft’s discoveries about the tiny moon Enceladus have been some of the most exciting of the entire mission at Saturn. What was once thought to likely be little more than a frozen ice world has turned out […]

A Moon Falling Apart: Grooves on Phobos Are a Sign of its Eventual Catastrophic Fate

The unusual grooves on Phobos’ surface, such as those on the left side of this image, are now thought to be caused by tidal stress. The large crater Stickney is in the upper portion of the image. Image Credit: NASA/JPL-Caltech/University of Arizona

Phobos is the largest of Mars’ two tiny moons, but 50 million […]

Cassini Completes Epic Flyby Through Geysers of Enceladus, Sends Back Stunning New Images

View of Enceladus and Saturn’s rings during the flyby on Oct. 28, 2015, at a distance of 106,000 miles (171,000 kilometers) from Enceladus. Image Credit: NASA/JPL-Caltech/Space Science Institute

The Cassini spacecraft has successfully completed its deepest dive through the water vapor geysers of Enceladus and is now sending back some fantastic images of the […]

Sampling an Alien Ocean: Cassini Prepares for Deep Dive Through Enceladus' Geysers on Wednesday

Artist’s conception of Cassini making a close flyby of Enceladus and its water vapor plumes. Image Credit: NASA/JPL

This coming Wednesday, Oct. 28, 2015, the Cassini spacecraft will make a historic close flyby (dubbed “E21”) of Saturn’s tiny icy moon Enceladus, not only passing very close to the surface, but also making the deepest […]

Dark Material in Fractures on Europa's Surface Is Sea Salt, New Research Suggests

The darker-colored material within the fractures and elsewhere on Europa’s surface might be sea salt brought up from the ocean below. Image Credit: NASA/JPL/Ted Stryk

For over a decade, scientists have been curious about the long fractures on Europa’s icy surface and the darker-colored material they contain, as well as other relatively young geological […]