The "Human vs. Machine" discussion will probably go on forever but a recent discovery on Mars got me thinking about it again. Related in an S&T blog (with a great 3-D image, BTW) it talks about how after one of the Mars rovers passed by a meteorite did one of the human controllers on Earth see it in pictures and had the rover turn around and go back. Makes me wonder how many other discoveries have been missed over the years as the unthinking rovers rolled over the potential discoveries without knowing they were there. It'll be interesting years from know when humans follow the rovers' tracks and discover who-knows-what. There's just no substitute for human curiosity (at least not until the machines become smarter than us and take over...) http://www.skyandtelescope.com/community/skyblog/newsblog/52642607.html patrick