QUESTION:
Generally, what source elements, minerals, etc., would be or could be on
Mars that could greatly simplify terraforming the planet?

ANSWER from Bob Haberle on August 8, 1997:
CO2 is the most important gas. It's in the atmosphere and maybe present in
the surface as dry ice or adsorbate. To terraform Mars you would need lots
of it (many hundreds of millibars) to start transforming the climate. Then
you would need oxygen and nitrogen. Oxygen is present but it may be hard to
get it into the form you want (gas). Nitrogen is a big if. We just don't
know if there is enough of this around.

Perhaps the biggest obstacle to terraforming Mars is the amount of energy
and time that would be required to do it. Some estimates put this at 100's
of thousands of year.

Robert M. Haberle
Space Science Division
NASA/Ames Research Center