A NASA-sponsored study found there’s not enough carbon dioxide on Mars to help terraform the planet in any way to make it habitable for humans.
If true, there goes pretty much the entire basis for Elon Musk’s plans to make Mars the kind of place humans might walk freely around on.
Musk has repeated his claim Mars was a “fixer-upper” of a planet several times. Most famously, he told Stephen Colbert in 2015 that the fastest way to make Mars habitable would be to “drop thermonuclear weapons over the poles”, which would melt carbon dioxide ice and create a greenhouse effect.
That thicker atmosphere would allow liquid water to exist on the surface.
The atmospheric pressure on Mars is around 0.6% of Earth’s. But because Mars is further away from the Sun, researchers say a CO2 pressure similar to Earth’s total atmospheric pressure is needed to raise temperatures enough to allow for stable liquid water.
Yes, the most accessible source is CO2 in the polar ice caps. Scientists say spreading dust on it to absorb more solar radiation or explosives could release it, but even totally vaporised ice caps would only contribute enough CO2 to double the Martian pressure to 1.2% of Earth’s.
That analysis has just been completed off the back of 20 years of additional spacecraft observations of Mars.
Another option might be heat the Martian soil to release CO2 particles, but NASA’s estimates suggest that could only contribute an extra 4% of the required atmospheric pressure.
Even a deep dive for carbon locked in mineral deposits below the surface would yield another 5% of the pressure needed to keep liquid water stable on Mars. And we’d have to strip mine the entire planet to a depth of around 100 metres.
“Our results suggest that there is not enough CO2 remaining on Mars to provide significant greenhouse warming were the gas to be put into the atmosphere,” Bruce Jakosky of the University of Colorado said.
“In addition, most of the CO2 gas is not accessible and could not be readily mobilised. As a result, terraforming Mars is not possible using present-day technology.”
Just to make the point clear, here it is in pictures:
Evidence shows it was likely there was a time when Mars did have flowing water, but so much of the ancient atmosphere that made it possible has been stripped away by solar wind and radiation that, if it were suddenly protected again, it would take about 10 million years just to double Mars’ current atmosphere, according to the team.
It did suggest “redirecting comets and asteroids to hit Mars” could speed up the process, but “many thousands would be rquired”.
The team does, however, make the point that it’s not possible to thicken Mars’ atmosphere in any meaningful way with current technology.