Genetically engineered bacteria could be the first creatures to colonise the Red Planet, while rock-eating bugs could help release carbon dioxide from its crust.
The carbon dioxide would cause global warming, slowly making Mars warmer and moister. Ultimately, the hope is that terraforming Mars could make the planet hospitable to humans.
But special bacteria would probably be the first colonisers, says molecular biologist Julian Hiscox of the University of Reading. 鈥淲e鈥檇 take Earth bacteria living in the conditions most similar to Mars and play Darwin, getting them closer by selection and genetic engineering,鈥� he told a Mars terraforming conference at NASA鈥檚 Ames Research Center.
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Antarctic bacteria, for instance, already endure temperatures well below freezing. By growing these cells at ever lower temperatures and selecting those that thrive, it will be possible to breed bugs suited to an extraterrestrial existence, Hiscox says.
The tools of molecular biology could improve them further by stealing traits from other Earth bacteria that could give them a vital edge on Mars. The wish list includes a tolerance of harsh chemicals, resistance to dryness and radiation and the ability to produce ultraviolet-absorbing proteins.
As well as protecting the cells, such UV 鈥渟unscreen鈥� proteins could power them too, suggests Penelope Boston of the University of New Mexico in Albuquerque. These proteins could be coupled to the existing photosynthetic machinery in bacteria, she says.
Boston also thinks that rock-digesting bacteria she has found in caves could help recycle trapped CO2 in Mars鈥檚 crust.
On Earth, CO2 and other gases are released by the movement and re-cooking of huge tectonic plates. Mars doesn鈥檛 have any similar tectonic activity. So she proposes establishing a 鈥渂iotectonic鈥� cycle instead, using communities of these microbes.
鈥淭heir work is extremely rapid,鈥� Boston says. When you walk by cave walls where these bacteria live, she says, 鈥渢he rock is literally raining down鈥�.
For more reports from the Mars terraforming conference see 快猫短视频 magazine on 21 October 2000.