Whenever the topic of non-Earth life in space is broached, Saturn's moon Titan always seems to come up. Aside from Earth, Titan may well have one of the most hospitable (and, more importantly, Earth-like) atmospheres and environments in the solar system. Granted, there are a few noteworthy differences. Although Titan has climate zones and weather patterns, its distance from the sun means that it's considerably colder than Earth. The seas of Titan are composed of liquid Methane, while whatever water might exist on the planet is likely frozen well beneath the surface.
Still, it's a promising specimen in the search for life - which may be why scientists and researchers are so fascinated by it.
Unfortunately, the exploration of Titan's surface isn't exactly simple. The vast distance between Titan and Earth means that communication with any probes sent to the moon's surface would take hours to get there; probes would thus have to possess a heretofore unprecedented degree of autonomy.
"If the probe has been floating in a methane sea for months and finally approaches shore, it must begin taking pictures of newly visible land," explains engineer Trey Smith of NASA's Intelligent Robotics Group. "If a methane-dwelling octopus swims by, it must notice and begin taking pictures."
He's only half-joking.
On the surface of a remote lake in Chile, researchers from NASA Ames Research Center and The Search For Extraterrestrial Intelligence Institute have spent the past three weeks field-testing a new type of probe known as the Planetary Lake Lander. Given that there are no hydrocarbon seas on Earth, the lake - located under the disappearing Echaurren glacier, where the probe has been set to work monitoring its decline. The location, explains Smith, was chosen because it's an ideal spot to test the probe's capacity to notice subtle environmental changes.
The probe's actually been here for a bit longer than the past three weeks, of course- it's been exploring its surroundings with ever-increasing awareness since 2011, with the researchers only paying it periodic visits to upgrade and check in on it's status. Since the probe first started its tours of the lake, it's send six e-mails to its creature, each one accurately predicting the weather in the region.
"My colleague posted on Facebook that he had just sent Curiosity its instructions for the day," joked Nathalie Cabrol of the SETI Institute. "I wrote "my robot is smarter than yours - he's the one sending me emails!" We will stop it short of writing our papers."
The robot might be smarter than most probes at the moment, but it's not exactly ready to ship out to Titan for quite some time yet. The team still needs to nail down the robot's selectivity in what data it records and transmits, owing to the extreme distance between Earth and Titan. Because of this distance, it takes over a joule of power to send one bit of information to Titan from earth, according to roboticist Liam Pedersen. To put that into layman's terms, transmitting a single black-and-white image would completely drain a D-cell battery.The Planetary Lake Lander must therefore be able to recognize which data it should (and should not) transmit.
According to Cabrol, this technology could have applications on Earth, as well. The ability to equip probes with selective data capture could, for example, be used to monitor ocean chemistry or even keep watch on the sky, alerting us of incoming pulsars, quasars, supernovas, or asteroids.
"I don't know if we are smarter than the dinosaurs, but we have more technology than they did," notes Cabrol. "If we want to continue surviving on this planet, we're going to have to get better at monitoring our environment." The technology being developed with the Planetary Lake Lander could, in the long term, be the first step towards accomplishing this.
In the short-term, meanwhile, a 2016 proposal to Titan's Ligeia Mare region is still seeking funding, having lost out to a Mars Lander mission. Should the funding for the proposal not come through this year, it will be too late: the probe needs to launch in 2016 if it is to arrive on Titan before 2025, when the polar region will lose direct contact with Earth. Should this happen, the mission will not be possible until 2040, meaning the team would need to wait another fifteen years before exploring Titan's seas.
This, says Cabrol, would be a shame, as the seas could very easily contain life.
"Methane has its problems for life, but that being said, it could just be that our intellect is limited. And if I had to bet, I would bet on that."