What's the News: NASA's considering launching a boat from Earth, hurling it 746 million miles through space, and plopping it onto one of the minus-290 degrees Fahrenheit methane oceans of Titan. This mission to Saturn's largest moon would the first of its kind to probe an alien ocean and---depending on the weather conditions---could be the first spacecraft to witness extraterrestrial rain. If the proposed mission beats out two other finalists, it could launch within the next five years. "Titan is an endpoint [in] exploring ... the limits to life in our solar system," project leader Ellen Stofan told New Scientist. "We're going to be looking for patterns in abundances of compounds to look for evidence for more complex or interesting reactions." The Mission:
If the mission, dubbed the Titan Mare Explorer (TiME), lifts off in 2016, it should reach Titan by 2023 and then parachute onto one of its large lakes, such as Ligeia Mare or Kraken Mare. These lakes are prime destinations because, unlike most of Titan's lakes, they span hundreds of kilometers in length, similar in size to the Great Lakes.
After splashing down, TiME would drift with the wind and ocean currents on Titan to complete a 96-day mission to identify the alien ocean's complex organic molecules. Powered by the heat of decaying plutonium it brought along on the mission, the probe could gauge the temperature, humidity, and winds at the lake's surface and also use sonar to create a lake-bottom profile. It would also take pictures of the ocean and surrounding skies.
Nuclear generators seem to be the best option to power the probe because batteries would only provide power for a limited time, and the moon's atmosphere is too thick to make solar energy feasible. NASA has used nuclear energy to power spacecraft in the past, including the Cassini probe.
What's the Context:
Titan's lakes are a mixture of methane and ethane, hydrocarbons that are gases on Earth, but liquids at the moon's frigid temperatures. From past research, scientists know that the moon hosts complex, carbon molecules, including acetylene, which has prompted some to speculate that Titan also hosts life. But as planetary scientist Ralph Lorenz told Discovery News, "We have no expectation of finding living things ... But we think the complexity of the organics (on Titan) can lead us to the steps toward life."
In 2005, NASA's Cassini spacecraft successfully parachuted Europe's Huygens probe onto Titan, inspiring the current plan to parachute a boat onto Titan's waters.
Recently, scientists have uncovered more evidence for underground oceans of water on Titan, while other researchers have suggested that the moon's atmosphere was a result of comet impacts.
Not So Fast: TiME still has to beat two other possible missions---one involving setting up seismic monitoring stations on Mars and the other involving a comet-hopping probe---before it can become anything more than a proposal. The Future Holds: As a finalist, the TiME team has already been awarded $3 million to flesh out their idea. NASA will award the winning proposal $425 million next year. Image: NASA