Case closed. It’s ‘almost impossible’ to transform Mars to become habitable
Let a Mars planetary expert explain why..
Is it possible to create a viable atmosphere on Mars? was a fact-check asked on Metafact, a place to source the facts direct from experts. This answer was originally published at metafact.io.
Dr Francois Forget, French planetary scientist specialising in Mars answered this question: “Extremely Unlikely”:
A “viable atmosphere” could be defined as an atmosphere that would allow humans to walk without spacesuit on Mars (i.e. with only warm clothes and an oxygen mask). This would require a surface pressure of at least 250 mbar, while the mean surface pressure on Mars is currently 6 mbar.
It is almost impossible to import the equivalent of 250 mbar of gases on Mars from another planet or from comets. It corresponds to about 10¹⁵ tons of gases, while a a typical rocket can send only a few tons toward Mars… One could divert comets or asteroids toward Mars but it would require about 1 million of 1 km-radius comets to create a viable atmosphere.
Unlike what suggested in the 1980s-1990s, the new era of Mars exploration spacecrafts that have continuously studied Mars since 1997 have demonstrated that there is very little amount of potential gases available to create a 250 mbar. Frozen CO2 ice reservoirs have been discovered on the surface and in the subsurface by radar but heating and subliming them would add a maximum of ~10 mbar in the atmosphere. Heating the regolith could also desorb CO2 from the regolith, but only a few millibars.
The only possible solution would be to “burn” or chemically process Carbonate Rocks (which contains carbon dioxide molecules) from the surface to release CO2 into the atmosphere. One problem is that very little Carbonate reservoir has been identified at the surface of Mars, in spite of intense research by remote sensing instruments. Furthermore if extensive subsurface carbonate reservoir are found the mining work and the energy needed would be gigantic.
Read all the answers so far here and discuss with these experts directly, including with Dr Chris McKay of NASA.