As the title says, Opportunity has driven onto Mars, making that 2 fully functioning rovers to do some great scientific work. Congratulations NASA, its great to see you guys back! Live coverage here: SpaceFlightNow
This usage of 'bots is really starting to open up the whole space research field. Cheaper than flying some guy with a pickaxe to Mars. Safer too.
This is great news to have Opportunity & Spirit working on Mars. "NASA's Mars rover Opportunity spied hints yesterday of a mineral that typically forms in water -- a finding that could mean the dry and dusty Red Planet was once wetter and more hospitable to life." http://www.boston.com/news/nation/articles/2004/01/31/mars_rover_notes_hints_of_mineral_typically_formed_in_water/
The hematite *can* be formed with water, but its not the only way. Volcanic activity also creates this mineral - so they're going to have to do a little more work in order to definitely say that its from water. Looking at the images from Mars, though, its hard not to imagine water having once flown across the planet...but billions of years ago (if it had been only millions, there wouldn't be as many craters visible, they'd have been eroded away significantly). D
I think now we should start seeing some real interesting data coming from the rovers... not just pretty pictures (though they are fun and also help the scientists). The two rovers will soon begin some real scientific work. The future is bright!
The upper layer of the bedrock was shown to be hematite which indicates non volcanic methods of creation.
I certainly hope that this thesis will be proven. Finding indication of water on Mars will be a well deserved boost for NASA and the future of space exploration.