First Breaks Seen in Treads on Curiosity Rover's Wheels, But the Journey Continues

MAHLI view on sol 1641 of two of the raised treads (grousers) on the left middle wheel of the Curiosity rover which recently broke, including the one seen partially detached at the top of the wheel. Photo Credit: NASA/JPL-Caltech/MSSS

As the Curiosity rover continues its traverse among the buttes and sand dunes of Gale […]

A Martian Paradox: Curiosity Rover Findings Raise New Questions About Water on Ancient Mars

View from Curiosity of the Yellowknife Bay rock formation. Drilled samples here and elsewhere provided evidence that this region used to be at the bottom of a lake, but also that there are little or no carbonate mineral deposits, which should have been produced if the carbon dioxide atmosphere was thicker and warmer billions […]

Evidence from Curiosity Rover Shows Mars Once Had Oxygen-Rich Atmosphere

Mars’ atmosphere is thin, dry, and cold now, but it used to be thicker and contained a lot more oxygen. Image Credit: ESO/M. Kornmesser

Mars’ atmosphere is thin and cold, composed primarily of carbon dioxide along with other trace gases and some water vapor. Evidence has continued to mount, however, that the rarified atmosphere […]

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 […]

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 […]

Cassini Sends Back Spectacular New Images of the North Pole Region of Enceladus

New high-resolution view of the north polar region on Enceladus, showing a cratered surface crisscrossed by many cracks. Image Credit: NASA/JPL-Caltech/Space Science Institute

The Cassini spacecraft has just successfully completed the first of three final close flybys of Saturn’s moon Enceladus, and has sent back some spectacular images of the northern regions of this […]

Cassini Begins Series of Three Close Flybys of Saturn's Water Moon Enceladus

Illustration of Cassini’s “E-20” flyby of Enceladus, which will provide new, detailed views of the moon’s north polar region. Image Credit: NASA/JPL-Caltech

Starting today, the Cassini spacecraft is making the first of three scheduled close flybys of the moon Enceladus, which will provide the first good look at the north polar region of the […]

New Evidence From Cassini Indicates Saturn's Moon Enceladus Has Global Subsurface Ocean

Diagram depicting the interior of Enceladus, with the global ocean between the ice crust above and the rocky core below. The jets of water vapor erupt from fissures at the south pole. Image Credit: NASA/JPL-Caltech

Along with Jupiter’s moon Europa, Saturn’s moon Enceladus is considered to be one of the best places to look […]

New Study Helps Answer Mystery of What Happened to Mars' Early Atmosphere

Mars used to have a thicker atmosphere and water on its surface, but what happened to that atmosphere has been a mystery. New research may finally help answer that question. Image Credit: M. Kornmesser/ESO

The question of how Mars changed from a once wet world to the much colder and drier one we see […]