Space scientists in the US and UK are planning an incredible mission to go sailing on an alien lake on the far side of the solar system.
They are proposing a mission in NASA's low-cost Discovery series to launch an unmanned, nuclear-powered "boat" to Saturn's biggest moon Titan in 2015.
It would bob about on a vast sea of liquid methane called Ligeia Mare, radioing home photos and other data for six months.
Ligeia Mare is more than 300 miles wide and bigger than America's vast Lake Superior. The space scientists believe it is big enough that they can target their probe to dive straight into the lake.
The mission, called TIME (Titan Mare Explorer) comes after the British team successfully soft-landed a European probe on Titan - the most Earthlike world in the solar system - in January 2005. Titan, which is bigger than our own Moon, has rivers, lakes and coastal features just like our planet - though they are formed by methane, not water.
Europe's lander, called Huygens, sent home pictures of them as it parachuted through Titan's thick orange atmosphere. But it only worked for less than an hour on the surface before losing power. Its sister probe, NASA's Cassini craft, has since discovered clouds and rain on Titan during flybys as it orbits Saturn.
The new TIME probe to Titan will be built by scientists who created Beagle 2, the British craft that crashed on Mars on Christmas Day 2003, together with a US company, Proxemy Research of Maryland.
The Brits are led by Professor John Zarnecki, head of the Centre for Earth, Planetary, Space and Astronomical Research at the Open University in Milton Keynes.
His previous successes included building a camera for the Hubble space telescope, a dust detector on a probe to Halley's Comet and Beagle 2 with mutton-chopped colleague Professor Colin Pillinger.
He is also a project leader on a mission called Rosetta that is currently flying to another comet, called Churyumov-Gerasimenko, and Europe's ExoMars mission to put a rover on the surface of the Red Planet.
Professor Zarnecki told Skymania News: "It is a relatively small craft targeted to do one thing and so relatively low-cost. Titan is a very active place chemically in the atmpshere and on the surface. We want to discover more about Titan's methane weather cycle - like the water cycle on Earth.
"We want to determine the depth of the lake and if it is murky or clear and what is floating in it, plus look at the shorelines. We'd also want to look for organic materials. Understanding Titan better might also tell us more about whether it is possible for life to develop there."
Last year, NASA discovered a sea of water and ammonia 60 miles beneath Titan's crusty surface. Professor Zarnecki believes primitive life may exist there, kick-started by heat from the orange moon's core.
He said: "We know that Titan is swimming in organic chemicals. There has got to be some energy down there and it would not take much energy to allow life to begin."
Picture: The giant lake Ligeia Mare pictured by the Cassini spaceprobe. (Credit: NASA).
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