Terraforming Mars would make it more similar to Earth, creating an environment capable of supporting life as we know it.
Detlef van Ravensweig/Science Photo Library
Releasing iron rods the size of glitter particles into the Martian atmosphere could raise the planet’s temperature enough to melt water and support microbial life.
Making the Red Planet’s surface habitable for Earth-like life – a process known as “terraforming” – will be a complex one, but a key part of it will be raising the surface temperature above the current median freezing point of -65°C (-85°F).
Some have suggested placing mirrors on the Martian surface or pumping methane into the atmosphere, but these ideas are difficult to implement because the necessary raw materials would need to be shipped from Earth.
Now Edwin Kite of the University of Chicago in Illinois and his colleagues have found that a relatively tiny dust cloud made from iron or aluminum rods (each about 9 micrometres long and 160 nanometres wide) mined from Martian rocks could warm the planet by about 30°C over the course of a few months to more than a decade, depending on how quickly the particles are released.
These rods, each about 9 micrometers long and 160 nanometers wide, are carried by winds from the surface into Mars’ upper atmosphere, where they will remain for about 10 years, trapping heat from the surface and transmitting sunlight.
Kite and his colleagues modeled how the rods respond to light and fed that information into climate simulations, which showed that the increased temperature and pressure would be enough to support liquid water and possibly oxygen-producing bacteria in parts of Mars.
They also found that to achieve this warming, it would be enough to release the fuel rods at a rate fast enough to power about 30 garden sprinklers — a total of 700,000 cubic meters of metal per year, or about 1% of Earth’s metal production.
“When we did the calculations, we found that the amount of man-made dust we needed would be surprisingly small — much less than we would need to create the same amount of warming with man-made greenhouse gases,” Kyte says.
While mining the Martian surface would still be difficult, Kite says this would be 5,000 times more efficient than any warming method proposed so far.
One of the big uncertainties in the simulations is how the tiny bars interact with water in the Martian atmosphere, which could have unexpected effects such as causing the water to collect around the dust and rain down back to the surface, reducing global warming.
It’s an intriguing idea that could work if the particles remained in the atmosphere long enough, says Manoj Joshi of the University of East Anglia in the U.K. But even if the amount of metal needed was small, it would still require a huge manufacturing effort, he says.
Joshi said there are also ethical questions about whether it’s OK to alter the atmosphere of another planet: “Mars is so unexplored and we don’t know much about it. Is it OK to alter a planet in this way?”
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(Tag ToTranslate) Mars
