What would it cost to terraform Mars?
Claim One
What would it cost to terraform Mars?
My response: Terraforming Mars and the Limits of Engineering Optimism vs. further researching Earth and repairing any damage.
Observation
Mars has no breathable atmosphere, weak gravity, no global magnetic field, lethal surface radiation, extreme cold, and almost no accessible liquid water. These are measured facts from orbiters, landers, and rovers.
Hypothesis
If Mars could be terraformed into a human-suitable world, then current or near-future technology must be capable of altering the atmosphere, temperature, radiation shielding, and water stability at a planetary scale.