NASA is designing a robot submarine to explore the ultrachilly, hydrocarbon-filled seas on Saturn’s moon Titan — the only body in the solar system, apart from Earth, with liquid on its surface. Researchers have been testing the probe with a bucket-sized mock alien ocean in a lab.
The seas of Titan are very different from their counterparts on Earth: instead of seawater, Titan’s seas consist mainly of a frigid mixture of methane and ethane, at a temperature of around minus 300 degrees Fahrenheit (minus 184 degrees Celsius). That’s what NASA’s Cassini spacecraft and its Huygens probe, which landed on Titan in 2005, found.
The plan is to send the autonomous submarine into the largest sea on Titan. called Kraken Mare, from the name of a Scandinavian sea-monster and the Latin word for “sea,” the extraterrestrial sea covers 155,000 square miles (400,000 square kilometers) of the moon’s surface. (The second-largest sea on Titan, about a quarter the size of Kraken, is Ligeia Mare, named after one of the monstrous sirens of Greek mythology.) [See Photos of Titan’s Oceans].