elisabeth: according to nasa s curiosity rover, the answer is yet. in fact there s a lot. we just can t see it. does this mean maybe brian can go one day? brian: the scientist behind the study at poly tech nick institute joins us to explain. this is great news, isn t it, laurie? yes. we re excited to have discovered water in the dirt beneath our wheels. brian: what does it mean? what we did, we landed curiosity on mars a year ago and been exploring the floor of this wonderful crater. one of the first things we did was to scoop you up soil and feed about half a baby aspirin s worth into our oven and heat it up to three times hotter than your ovens at home. about 2% of the soil by weight is water that s chemically balanced.