Space boat to cruise for extraterrestrial life
Earlier this year NASA announced the concept of a spacecraft powered by electric-field sails riding the solar wind, cruising at unthinkable speeds of up to 180,000 Kph. Now, in addition to a sailing spacecraft, NASA is thinking about building a boat to explore extraterrestrial seas. Specifically the seas and lakes of Titan, Saturn's largest moon. Last month the agency awarded $3 million for scientists to develop the concept.
Titan's lakes are not made of water of course. They are a combination of liquid methane and ethane, with maybe some nitrogen as well. So far scientists have identified 400 lakes, ranging from a few square kilometers to well over 100,000 square km. The lakes form the same way our water lakes form on Earth. Evaporation forms clouds, then the clouds rain hydrocarbons back down to form rivers and lakes. Titan is the only world in our solar system, outside of Earth, that has this kind of liquid cycle.
The only way to study such liquid is to do in-situ studies, meaning right there on the lake. So the space boat, Titan Mare Explorer, will parachute in, splashing down on Titan's largest lake, Ligeia Mare. The goal is to analyze the depth, temperature, shorelines and chemistry of the lake. Scientists know there is methane and ethane, but there may also be the possibility of more complex organic compounds. The most exciting possibility is to find some of the kind carbon-based chemical combination that resulted in life on Earth.
Some scientists already think Titan holds the greatest potential for extraterrestrial life. Perhaps even more so than Mars. The challenge is that a complicated arrangement of hydrocarbons that transforms into animated life on Titan won't look anything like life as we know it. There's no water, so no helical structure of DNA. Titan is also freezing, nearly -180 degrees Celcius. While it might seem implausible to expect biochemistry to work at such temperatures the answer is scientists just don't know. They have little experience dealing with chemistry at such extremely low temperatures. One thing they do know, however, is that if there is life on Titan it began separately and will have a unique origin from life on Earth. And this possibility leads to the more profound idea noted by Jonathan Lunine, a co-investigator working on the development of Titan Mare: If there is life on Titan—meaning organic chemistry that can work in such harsh environments—then life may be a common outcome within the cosmos.
Currently the Titan Mare is one of three concept finalists in NASA's Discovery Mission. The others are a monitoring station for Mars and a lander that would explore a comet. NASA will review the developed concepts in 2012 and the winner will launch the $425 million mission sometime in 2016.
[via Scientific American]
This post was originally published on Smartplanet.com