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!
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.
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.