Scientists Reconsider Habitability of Saturn's MoonScientists Reconsider Habitability of Saturn's Moon
Recent findings from NASA's Cassini spacecraft are causing scientists to rethink the possibility that there may be life on Saturn's cloudy moon Titan. Analyzing data from Cassini's recent Titan flybys, scientists announced last week that several of the key elements crucial for life on Earth are also present on Titan, including liquid reservoirs, organic molecules and ample energy sources. Discovered in 1655 by a Dutch astronomer, Titan is the second largest moon in the solar system apart from Jupiter's Ganymede. Scientists are interested in Titan because it reminds them of how Earth was billions of years before life existed. Titan is colder (-289 degrees Fahrenheit, or –178 Celsius) than primitive Earth was, but it has a dense nitrogen-rich atmosphere and a natural process for producing hydrogen and carbon containing molecules. The Sun's ultraviolet light reacts with nitrogen and methane, producing a steady stream of organic materials that fall steadily onto the moon's surface. If life does exist on Titan, a good place to look for it may be in hot springs connected to hydrocarbon reservoirs. Further fueling speculations about life on Titan are recent findings that microscopic organisms that live in extreme environments on Earth are hardier than anyone ever imagined. One recently discovered species could live in briny environments ten times saltier than seawater. Another species found in Yellowstone National Park could live off nothing but hydrogen. Perhaps most relevant for life on Titan, scientists have discovered within the past two decades several species of bacteria that thrive in temperatures ranging from 23 to 68 degrees Fahrenheit (-5 to 20 degrees Celsius) and use methane to produce energy.