Terraforming means transforming a planet’s climate to make it Earth-like and capable of supporting Earth life, including humans, to the point that no artificial life-support systems are required.
Such a project would require raising Mars’s temperature to the point that it could support liquid water on its surface. The Martian atmosphere would have to be thickened by releasing greenhouse gases already present on the planet, noted researchers led by Bruce Jakosky, principal investigator of NASA’s Mars Atmosphere and Volatile EvolutioN mission (MAVEN), which studies the Martian atmosphere, and by Christopher Edwards of Northern Arizona University (NAU).
While Mars’s polar ice caps and some of its rocks contain carbon dioxide, the amount present is not enough to sufficiently warm the planet should they be released.
For the study, Jakosky and Edwards documented all known surface and subsurface CO2 based on data collected by Mars rovers and orbiters over the last 20 years.
According to their calculations, the planet has enough CO2 reserves to triple its atmospheric pressure. This is just one-fiftieth of the CO2 necessary to sufficiently increase the atmospheric pressure to the point that people could walk on the surface without having to wear spacesuits.
Additionally, if released into the Martian atmosphere, the Red Planet’s CO2 would warm the planet by less than 18 degrees Fahrenheit (10 degrees Celsius), far too little to raise planetary temperatures from their current average of minus 80 degrees Fahrenheit (minus 60 degrees Celsius) to the point of habitability for humans.
During Martian winters, temperatures are cold enough for CO2 to freeze on the planet’s surface.
Accessing the CO2 and releasing it into the atmosphere would also prove to be a challenge. It would require detonating explosives on the polar caps to release the gas or using explosives elsewhere to increase the level of atmospheric dust to land on the polar caps and heat them up with solar energy, the researchers state.
Future technologies could potentially make terraforming Mars a possibility, Jakosky and Edwards acknowledge.
“With current technologies, we just don’t see that there are any viable options,” Edwards said.
While Mars is the closest and most accessible planet for humans to settle, the concept of terraforming remains largely a characteristic of science fiction and mythology, Jakosky said.