Some of the Sojourner images show rocks which appear to be rounded suggesting erosional activity by water on Mars. Carbonates in Martian meteorite ALH84001 are believed to have formed at low temperatures with water and possibly bacteria, too. Therefore, there are several different types of rocks from Mars, some formed at high temperatures and some believed to have formed at low temperatures. Of course we have analyzed only a very small number of rocks from Mars. To get the complete story of how the planet formed, how much water was there, if bacteria existed or still exists on Mars, we need to bring back rocks and examine them with more sophisticated types of equipment that we have here on Earth.
Weightlessness is a wonderful feeling and great sense of freedom.
It does take a few days to adjust to it, but after a while it starts to feel like a very natural way to be. It was a few days before my balance was restored, and a few weeks before my muscles were back to normal. The first time I stood up was a bizarre sensation and I had legs that felt unbelievably heavy and required a seemingly huge effort to move. And curiously the soles of my feet were very tender as I had not walked on them for 20 weeks. To my thinking, the idea of stepping foot on, and visiting another planet would be one of the most extraordinary adventures that anyone could possibly do.