Mirrors in orbit around Mars could create Earth-like conditions on a small patch of the planet鈥檚 surface, according to a NASA-funded study. The extra sunlight would provide warmth and solar power for human explorers, but some experts say the mirrors may be hard to deploy.
快猫短视频s and science-fiction authors have long dreamed of turning Mars into a more Earth-like planet for future human colonists. The process, called terraforming, involves thickening Mars鈥檚 atmosphere and increasing its temperature. But schemes to transform the entire planet would take centuries and would require enormous resources.
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Now, Rigel Woida, an engineering student at the University of Arizona in Tucson, US, is investigating the possibility of 鈥渢erraforming鈥� just a small patch of the planet鈥檚 surface by focusing sunlight on it from orbiting mirrors.
He received $9000 to study the idea from the NASA Institute for Advanced Concepts (NIAC) in Atlanta, Georgia, US.
The concept calls for 300 reflective balloons, each 150 metres across, arranged side-by-side to create a 1.5-kilometre-wide mirror in orbit around Mars.
Balmy conditions
The mirror would focus sunlight onto a 1-kilometre-wide patch of Mars鈥檚 surface. This would raise the temperature in this patch to a balmy 20掳 Celsius (68掳 Fahrenheit) from Mars鈥檚 typical surface temperature of between -140掳 C and -60掳 C (-220掳 and -76掳 F).
The extra warmth would mean the astronauts would not need heavily insulated suits or living quarters, allowing them to work more easily. The extra sunlight would also boost power from solar cells.
And the higher temperature would melt any water ice on the ground. This could make precious liquid water available for astronauts to drink, and the water could also be used as a raw material to produce rocket fuel for the journey home, Woida says.
鈥淭he greatest hold-up to exploration, terraforming and colonisation of Mars is the lack of available materials,鈥� he told 快猫短视频.
He says astronauts could maximise the amount of available water by warming up a region that includes a frozen lake, such as the one near the planet鈥檚 north pole that was imaged by Europe鈥檚 Mars Express spacecraft (see Frozen lake shines bright in Martian crater ).
Dangerous radiation
Margarita Marinova of Caltech in Pasadena, US, who is not involved in the study, says the extra solar power would greatly benefit future Mars missions. 鈥淭his would be quite useful for many types of missions 鈥� both robotic and human,鈥� she told 快猫短视频.
She cautions, however, that deploying objects in space can be challenging, citing an experimental tether that broke during deployment from the space shuttle in 1996 and the failure of solar sail experiments. The orbiting mirror for Mars 鈥渋s not an easy project by any means鈥�, she says.
Woida points out another potential problem. If not carefully designed, the mirrors could focus harmful high-frequency radiation such as ultraviolet light onto the surface.
Mars鈥檚 thinner atmosphere would not filter these out like Earth鈥檚 does, so the balloons would have to be coated with materials that would reflect only visible and infrared light, he says.
In his concept study, Woida will work out the structural details of the balloons and study how much extra light from the reflectors reaches the Martian surface.
