Interactive · Mars
Terraform Mars
Push the sliders and find out what it would take — and how long.
The honest questions
Can Mars actually be terraformed?
In principle, partially. Warming Mars with super-greenhouse gases and orbital mirrors is physically plausible over decades to centuries. Building a thick, breathable atmosphere is far harder — Mars lacks the volcanic outgassing and magnetic field that sustain Earth's air, so it would leak away over geological time. Full terraforming remains a centuries-to-millennia project, if it is possible at all.
Why does liquid water need air pressure?
Because of the triple point of water: below about 0.6 kPa of pressure, liquid water cannot exist — it boils or freezes on contact. Mars' average surface pressure sits right at that edge, which is why raising the pressure is the key that unlocks lakes and rivers.
How long would terraforming Mars take?
Optimistic proposals put initial warming within a century; a breathable atmosphere would take many centuries to millennia of sustained, planet-scale engineering — assuming the physics cooperates. Anyone promising faster is selling something.
Where does the extra air and water come from?
Proposals include baking CO2 out of Martian carbonate rocks, vaporizing the polar caps, mining subsurface ice, nudging volatile-rich comets inward, and manufacturing super-greenhouse gases on an industrial scale. Each is an enormous engineering project on its own.