Scientists hope to send a robotic submarine into oceans that may lurk within a moon of Jupiter, in what could be the first exploration through liquid waters on another world.
Researchers have long speculated that under the icy shell that encases the moon, Europa, liquid water might harbor primitive life forms. A Europa mission is still years away, according to scientists; but in preparation for such an event, they plan to test a NASA-funded robotic probe under ice on Earth. Testing will take place next week in Lake Mendota on the campus of the University of Wisconsin, Madison, according to a Feb. 8 announcement from the agency. The sub is made to “swim untethered under ice, creating three-dimensional maps of underwater environments,” the announcement said. The robot would also “collect data on conditions in those environments and take samples of microbial life.” The project is led by University of Illinois at Chicago and NASA scientists.
After the Wisconsin tests, researchers said they plan to ship the probe to a permanently frozen lake in Antarctica for further trials. The vehicle, called ENDURANCE (Environmentally Non-Disturbing Under-ice Robotic Antarctic Explorer), is a $2.3 million project. It’s a follow-up to the Deep Phreatic Thermal Explorer, another NASA-funded project that finished underwater tests in Mexico in 2007, agency scientists said. Europa, slightly smaller than Earth’s Moon, is the fourth largest of Jupiter’s at least 16 moons, and is covered with whitish and brown ice. Beneath it, many researchers believe the moon may harbor the only global ocean of liquid water in our Solar System besides Earth’s. Images from NASA’s Galileo spacecraft have shown areas with similarities to Earth’s ice-floe covered Arctic oceans, suggesting the existence of water or warm “slushy” ice below, according to David R. Williams, a scientist at the agency’s Goddard Space Flight Center. Such an ocean could conceivably provide a home for living things. Europa’s interior is hotter than its surface, according to William B. McKinnon, a planetary scientist at Washington University in St. Louis. This internal heat comes from the gravitational pull of Jupiter and its other large moons, which stretch Europa’s insides in different directions and create friction. Most of the satellite is made of rock, according to McKinnon.
Repeated splitting and shifting of the surface ice, and disruptions from below, have reshaped Europa’s surface, Mcinnon continued. A result is that there are few visible impact craters, since the shifting would have erased these. The surface shows shallow cracks, valleys, ridges, pits, blisters, and icy flows, McKinnon added, none more than a few hundred yards or meters high or deep. The Italian astronomer Galileo discovered Europa 1610. Its name is said to have been first suggested by his contemporary, the German astronomer Kepler, who proposed naming Jupiter’s moons after the secret mistresses of Jupiter, king of the gods in Greek and Roman mythology. According to myth, Jupiter took the form of a bull to abduct Europa, a Phoenician princess.