With recent attention focusing on its sister moon Enceladus, Titan—Saturn's largest moon, and the second-largest moon in the solar system—has been neglected as a possible source of extraterrestrial life. While its -179°C/-290°F surface temperature and methane-rich atmosphere would seem to preclude what Star Trek's Dr. McCoy might refer to as "life as we know it," the possibility of methane-based life on the surface of Titan is both very real and entirely consistent with what we know of the planet's atmosphere. So when can we send a probe there, and what's the best way to explore the surface?
As Huygens fell to the surface of Titan, it recorded video of the planet's surface and broadcasted it to us. This is the unprocessed footage:
And here's a processed image from Huygens itself, following its landing. It is the only photograph ever taken from the surface of Titan:
The joint NASA/ESA proposal or a Titan Saturn System Mission (TSSM) would use an air balloon to survey the geography (very feasible, given Titan's thick atmosphere), and a lake-lander called the Titan Mare Explorer (TiME) to examine the chemical composition of one of Titan's many methane lakes. But the TiME lake-lander would have limited mobility, prompting Universe Today's Michael Habib to ask yesterday: why don't we take advantage of Titan's dense atmosphere, and the low viscosity of liquid methane, by just depositing a sailboat on the planet's surface and letting it explore?
Europa has taken precedence over Titan and Enceladus as targets of exobiological study, and even the Europa mission has a far-off 2030 deadline, but given recent interest in Enceladus as a possible habitat for extraterrestrial life it's not completely implausible that we'll send a probe to Titan within the next ten years—and what we find there may be worth the effort.