While NASA doesn’t have any definite plans to send a probe to study Jupiter’s moon Europa, many planetary scientists consider the exploration of this enticing moon to be a high priority. Evidence from the Voyager and Galileo spacecraft suggests Europa contains a deep ocean of salty water under an icy outer shell. NASA is, however, helping to fund a prototype of an underwater autonomous vehicle to investigate ice covered lakes here on Earth, to demonstrate if such a vehicle could operate in an environment similar to Europa. The next test of the vehicle will take place Feb. 12-15, 2008 in Lake Mendota on the campus of the University of Wisconsin, Madison.
The Environmentally Non-Disturbing Under-ice Robotic Antarctic Explorer, also known as Endurance, will swim untethered under ice, and collect data to create three-dimensional maps of underwater environments. The probe also will look at the conditions in those environments and take samples of microbial life. Later this year, researchers plan to ship the probe to a permanently frozen lake in Antarctica for more operations. The probe is a follow-up to the Deep Phreatic Thermal Explorer, a NASA-funded project that completed a series of underwater field tests in Mexico in 2007.
“We’re using extreme environments on Earth as our laboratory,” says Peter Doran, associate professor at the University of Illinois at Chicago. “Ice-covered lakes are good, small-scale analogs to what we might find on Europa.”
Mendota Lake is only 25 meters deep, while the lake in Antarctica, West Lake Bonney is 40 meters deep. Scientists believe that Europa’s ocean could be up to 100 kilometers deep.
Hot water drills will bore a hole for Endurance to enter the water. If all goes well, the probe will be tested again in 2009.
But many hurdles remain before an underwater vehicle could possibly head to Europa. Presently, Endurance is too massive to send on interplanetary travel. Scientists will also have to come up with a way to drill through Europa’s icy crust and lower the sub safely through the ice.
And before a probe would be sent to land on Europa, many scientists feel that an orbiting spacecraft would be the best way to study the moon. The Jet Propulsion Laboratory is currently working on a concept called the Europa Explorer which would deliver a low orbit spacecraft to determine the presence (or absence) of a liquid water ocean under Europa’s ice surface. It would also map the surface and subsurface for future exploration.