This is an incredible achievement.<p>The "key traces of water" is awe inspiring in itself. However, what is more impressive is that Opportunity is still chugging along 7 years longer than predicted and making these discoveries. Unfortunately, NASA is pretty bad at displaying successes and explaining why it is important.<p>The press release: <a href="http://marsrover.nasa.gov/newsroom/pressreleases/20111207a.html" rel="nofollow">http://marsrover.nasa.gov/newsroom/pressreleases/20111207a.h...</a>