For many decades, the idea of humans living on Mars has been the stuff of science fiction. Authors like Edgar Rice Burroughs, Ray Bradbury, Kim Stanley Robinson, and Arthur C. Clarke have offered dramatically different interpretations of what it might be like to live on the Red Planet.
Although there are no immediate plans to send a crewed mission to Mars, NASA hopes that this might be possible by the 2040s, especially if the proposed Artemis missions to the Moon are successful. Whatever the timeline, the intrepid explorers who eventually land on the Red Planet will face a world vastly different from our own. Compared to Earth, Mars has a drastically lower average temperature, low atmospheric pressure, low surface gravity, a thin atmosphere made mostly of carbon dioxide, dust storms, low light levels, ionizing solar and cosmic radiation, and unfarmable soil with a high nitrate concentration.
Although the Martian environment is far from ideal, that hasn’t stopped both planetary scientists and science-fiction authors from dreaming up ways to terraform it. One of the biggest questions is how to warm up the Red Planet, which has an exceedingly chilly median surface temperature of -85 °F (-65°C). The thin atmosphere makes it nearly impossible for water to exist on the Martian surface and results in most of the sun’s warmth quickly escaping.
Planetary engineers have long pondered how to make the Martian atmosphere more effective at trapping heat—essentially, the greenhouse effect that we are familiar with on Earth, with gases in the atmosphere keeping heat close to the surface. Previous proposals have suggested releasing heat-trapping chemicals such as chlorofluorocarbons (CFCs) into the Martian atmosphere. Ethical concerns aside, the logistics of such an undertaking would be immense, as all of those chemicals would have to be brought to Mars from Earth.
A new interdisciplinary study published earlier this month in the journal Science Advances takes a different approach. It suggests creating tiny nanorods from aluminum and iron from dust on the Martian surface. If released into the atmosphere, the researchers calculated that these tiny flakes of metal (just nine micrometers long) would persist for around 10 years. During that time, they would trap thermal infrared radiation and reflect sunlight back to the surface. Over the course of the decade, they could potentially raise the global temperature of Mars by over 50°F (30°C). Surprisingly, the researchers found that a relatively small amount of nanoparticles (released at a rate of 8 gallons, or 30 liters, per second) would be needed to achieve this, making them far more effective than the proposed release of CFCs.
However, despite these promising calculations, significant questions remain over this theoretical endeavor, including the obvious moral quandary: is it ethically sound to interfere with the atmosphere of another planet, especially when so much about it remains undiscovered?
Warming up the Red Planet:
- With an increased surface temperature, Mars could potentially be made warm enough to facilitate the formation of liquid water and possibly microbial life—or, in the right conditions, vegetation brought from Earth.
- However, even with warmer temperatures on the planet, future Martian colonists would still need to wear spacesuits, due to the exceedingly low pressure and unbreathable atmosphere.
- There is a huge range of temperature variations on the Red Planet. Daytime temperatures in the summer can reach close to 70°F (20°C), while the polar ice caps in the winter can plummet to -225°F (-143°C).
