WASHINGTON — The idea of transforming Mars into a more habitable world for humans is ubiquitous in science fiction, but would it be possible in real life?
Scientists are now proposing a new approach to warming Earth’s neighboring planet. They’re pumping man-made particles – similar in size to commercial glitter and made of iron or aluminum – into the atmosphere as aerosols to capture escaping heat and scatter sunlight toward the Martian surface. The idea would be to amplify the natural greenhouse effect on Mars, raising its surface temperature by about 10 degrees Celsius within a decade.
This alone would not make Mars habitable for humans, but the scientists who developed the proposal consider it a potentially feasible first step.
“Terraforming is the process of changing a planet’s environment to make it more Earth-like. For Mars, warming the planet is a necessary but not sufficient first step. Previous concepts have focused on releasing greenhouse gases, but these require large amounts of resources that are scarce on Mars,” said planetary scientist Edwin Kite of the University of Chicago, who helped lead the study, published this week in the journal Science Advances.
“The core points of our paper are a novel proposal to use artificially created nanoparticles to warm the Martian atmosphere, as well as climate modeling that suggests this approach could be much more efficient than previous concepts. This is important because it represents a potentially more viable method of modifying the Martian climate that could serve as the basis for future Mars exploration strategies,” Kite added.
NASA has sent robotic rovers to explore the surface of Mars and the InSight lander to explore the interior of the planet. The US space agency’s Artemis program is expected to bring astronauts to the lunar surface in the coming years for the first time since 1972 in preparation for possible future manned missions to Mars.
There are numerous challenges for human settlements on Mars: lack of oxygen to breathe, harmful ultraviolet radiation due to the thin atmosphere, salty soil unsuitable for growing crops, dust storms that sometimes cover large parts of the planet, and more. But the freezing temperatures are a serious obstacle.
“We want to show that the idea of Mars warming is not impossible. We hope our findings will encourage the broader scientific community and the public to investigate this intriguing idea,” said lead study author Samaneh Ansari, a doctoral student in electrical and computer engineering at Northwestern University in Illinois.
The mean surface temperature of Mars is about minus 85 degrees Fahrenheit. Because of the thin atmosphere, the sun’s heat on the Martian surface easily escapes into space. The proposal would aim to allow liquid water on the surface of Mars, which has water in the form of ice in its polar regions and beneath its surface.
The scientists proposed continuously releasing tiny rod-shaped particles – so-called nanorods – into the atmosphere at a rate of about 33 liters per second over several years.
“The idea is to ship either the material or, better yet, the manufacturing tool and manufacture the nanorods on the planet, since iron and aluminum are present in large quantities on the Martian surface,” Ansari said.
Researchers are aware of the potential for unintended consequences that terraforming another world for the benefit of humanity can bring. For example, scientists are keen to find out whether life existed on Mars in the past – or perhaps even today, in the form of microbes beneath the surface.
“Although nanoparticles could warm Mars, both the benefits and potential costs of doing so are currently uncertain. In the unlikely event that Martian soil contains irreversible compounds that are toxic to all life on Earth, for example, the benefit of warming Mars is zero,” Kite said.
“On the other hand, if a photosynthetic biosphere can emerge on the surface of Mars, that could increase the solar system’s capacity for human flourishing,” Kite added. “In terms of cost, if there is life on Mars, exploring that life could bring great benefits that justify strong protection of its habitat.”
