What is the chemical makeup of the Martian soil, and how does it differ over various landscapes? What may need to be added or altered to make it suitable for bacterial and plant life?

What if you find a virus on Mars? What if we take a virus from Earth to Mars? How would they behave? Would they be less or more contagious?

As of now scientists are almost sure life - at least in a bacterial form - existed on Mars some 16 mil. yrs. ago - as structures made by bacterias were found and prooved on a martial meteor found in Antarctica - is there a possibility to discover living bacterias either on the surface or below it? Could we expect there used to live a higher form of life?

is there a possibility of finding current or past microbial life in Martian caves? on Earth, plenty of bacteria live in these regions.

I heard from the news that according to the experiment some bacterias that can living in extreme situation on Earth have survived in Mars condition. Then is it possible that some bacterias same as that on Earth live in Mars?

is there any way to help spirt get unstuck from the sand pit?

Are the rovers that are sent to mars sterilized? What would happen if they carry earth's microbes to mars? will they evolve there?