by CHARLES WOHLFORTH & AMANDA R. HENDRIX
Composite infrared image of Saturn’s moon Titan from NASA’s Cassini spacecraft PHOTO/NASA/JPL/University of Arizona/University of Idaho/Public Domain via Wikimedia Commons
Saturn’s largest moon might be the only place beyond Earth where humans could live
The idea of a human colony on Titan, a moon of Saturn, might sound crazy. Its temperature hovers at nearly 300° below zero Fahrenheit, and its skies rain methane and ethane that flow into hydrocarbon seas. Nevertheless, Titan could be the only place in the solar system where it makes sense to build a permanent, self-sufficient human settlement.
We reached this conclusion after looking at the planets in a new way: ecologically. We considered the habitat that human beings need and searched for those conditions in our celestial neighborhood.
Our colonization scenario, based on science, technology, politics and culture, presents a thought experiment for anyone who wants to think about the species’ distant future.
We expect human nature to stay the same. Human beings of the future will have the same drives and needs we have now. Practically speaking, their home must have abundant energy, livable temperatures and protection from the rigors of space, including cosmic radiation, which new research suggests is unavoidably dangerous for biological beings like us.
Up to now, most researchers have looked at the Moon or Mars as the next step for human habitation. These destinations have the dual advantages of proximity and of not being clearly unrealistic as choices for where we should go. That second characteristic is lacking at the other bodies near us in the inner solar system, Mercury and Venus.
Mercury is too close to the sun, with temperature extremes and other physical conditions that seem hardly survivable. Venus’s atmosphere is poisonous, crushingly heavy and furnace-hot, due to a run-away greenhouse effect. It might be possible to live suspended by balloons high in Venus’s atmosphere, but we can’t see how such a habitation would ever be self-sustaining.
But although the Moon and Mars look like comparatively reasonable destinations, they also have a deal-breaking problem. Neither is protected by a magnetosphere or atmosphere. Galactic Cosmic Rays, the energetic particles from distant supernovae, bombard the surfaces of the Moon and Mars, and people can’t live long-term under the assault of GCRs.
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