If we're going to go out beyond our home planet and begin construction of colonies somewhere else, then one of the vital resources we're going to require is energy – and a new study says Saturn's biggest moon, Titan, has plenty of it.
Actually Titan has sufficient energy sources to keep the lights on for a colony the size of the United States, scientists say, including choices for nuclear power, solar power, wind power and hydropower.
Amanda Hendrix from the Planetary Science Institute and Yuk Yung from the California Institute of Technology utilized the details we think we know about Titan and some math based on related technologies here on Earth to come up with their deductions.
"Once propulsion challenges are overcome, allowing humans to travel great distances quickly without incurring significant radiation damage, Saturn's moon Titan is the optimal location in the solar system for an off-Earth human settlement," write the scientists.
That colony would have to be self-sustaining, as Titan sits about 1.3 billion kilometers (808 million miles) away from Earth, but it has the potential to be used as a platform for missions that go even deeper into space. Early robotic voyagers could use nuclear power and radioactive decay as an energy source, and that might work for humans too, if we took up sufficient kit to build a plant and excavated materials from the moon itself.
At the moment however, Titan's geology is too much of an enigma to be sure the nuclear power would work. What we do know is that there's adequate supply of methane on Titan – oceans of the stuff – which could deliver rocket fuel as well as hydropower options. While the low-lying seas and absence of rain mean rivers aren't frequently found on the moon, tidal power is a likelihood.
Scientists have detected strong tides on Titan, produced by the enormous pull of Saturn, and those tidal changes all get pressed through a small channel called Seldon Fretum or the Throat of the Kraken.
"The Throat of Kraken is basically the Strait of Gibraltar. We're pretty sure there's a very strong flow of liquid back and forth every Titan day. If you want reliable power that you know is going to be accessible, that's where I would go." planetary scientist Ralph Lorenz from Johns Hopkins University, who wasn't involved in the research, toldNew Scientist.
Although Titan is nearly 10 times further away from the Sun than the Earth is, solar power is a choice according to the scientists behind the new study – as long as we can construct sufficient panels. The brightest a Titan day ever gets is same as dusk on Earth, but Hendrix and Yung believe a solar farm as big as the surface area of the United States would be capable of supporting as many as 300 million people.
As for wind power, Titan does have powerful winds in its upper atmosphere, according to calculation made by the Huygens probe. At the instant however, we don't have the technology to construct floating wind turbines that could get up that high. Certainly, one of the study's running themes is the need to improve the technology we have here on Earth, from solar panels to turbines, ready for use on other planets. With hydrocarbon fuels pretty much out of the question due to the lack of oxygen needed to burn them, we're going to have to depend on these other options to maitain a base on Titan.
The study authors accept that they've skipped over some details in their work – we just don't know that much about Titan right now – but their study is a useful first step in working out how to make life livable up on Saturn's largest moon. And the initial signs are that Titan has sufficient natural resources to keep us going.
"While temperature, gravity and wind conditions on Titan mean that energy production efficiencies are generally lower than on Earth, Titan's wealth of natural resources nevertheless imply that energy production on Titan is a significant possibility," conclude the researchers.
The findings are due to be published in the Journal of Astrobiology and Outreach but until then can be found on the pre-print website arXiv.org.