Far beneath the icy crust of Saturn's small moon Enceladus, hydrothermal activity may be at work, activity similar to what is found in some life-friendly environments on Earth.
NASA announced that Mars' Gale Crater was once the site of a vast lake that appears to have filled up, dried out and filled up again repeatedly over a much longer period than wet conditions were believed to have persisted.
Curiosity has reached the base of Mount Sharp, its primary mission goal. It's a 3-mile-high mound of sediment that preserves a geologic record of Mars going back billions of years.
One of NASA's most senior and still-operational spacecraft reached a milestone: the rover Opportunity completed its first 25 miles traveling across the surface of Mars!
Recently, NASA administrator Charles Bolden rephrased the "Moon, Mars and Beyond" mission plan to better align the steps toward Mars with budgetary realities and to balance human space programs with more cost-effective robotic missions.
Let's take a moment to tally a few of 2013's highlights of astronomy and space exploration. In brief, it was a very good year on a number of fronts.
If you had to make a choice to shut down either the Mars rover Curiosity or that explorer of the Saturn system Cassini, would you deliver a pink slip to the young, eager, energetic newbie or force an early retirement on a veteran explorer who has delivered volumes of knowledge?
NASA's "Engineer with a Mohawk" has become a pop culture phenom (62,000 Twitter followers isn't too shabby). But under that comb beats the heart of a true explorer, as we found when he dropped by for a visit.
NASA's Curiosity rover on Mars has raised some eyebrows by something it has not detected: methane. And, much farther out, the Cassini spacecraft has made a positive detection of plastic in the atmosphere of Saturn's moon Titan.