June 16, 2014 - Astrobiologists are excited about the possibility of extraterrestrial life on Jupiterâ€™s moon Europa. Evidence suggests this icy moon is home to a vast subsurface ocean. But until tools land on the moon to drill through the ice, ice-penetrating radar is the best method researchers have to confirm the existence of an ocean below the moonâ€™s surface. Unfortunately, Jupiterâ€™s own radio
waves interfere with this process. But researchers believe they can use these radio waves to their advantage.
Phys.org explains that Jupiterâ€™s radio waves come from clouds of electrically charged particles trapped in the planetâ€™s magnetic field. In order to cut through the interference from Jupiterâ€™s loud radio signals, â€śa mission probing Jupiterâ€™s moons would need a relatively strong transmitter, a massive device that might be difficult to power and fit aboard the limited confines of a spacecraft.â€ť
But rather than putting a transmitter on a spacecraft to fight against Jupiterâ€™s radio signals, a new study suggests harnessing these radio waves to scan the planetâ€™s moons, including Europa. The studyâ€™s lead author, Andrew Romero-Wolf at NASAâ€™s Jet Propulsion Laboratory, explains, â€śThe technique we are developing could not only provide a solution to that problem, it could turn it into a strength.â€ť He continues,
As Phys.org describes, this process, known as interferometric reflectometry, would work by positioning a spacecraft between Jupiter
and one of its icy moons, which would monitor decametric emissions from Jupiter
and echoes of signals reflected off the moon. This process would enable researchers to determine the thickness of the moonâ€™s ice shell and its oceanâ€™s depth.
Experts believe Europa has two-to-three times the volume of all the liquid water on Earth, so Europaâ€™s ocean is likely to have a wide variety of ecosystems. And a recent study suggests that the building blocks for life are common on this icy moon.
Romero-Wolf is excited about the information that can be acquired by utilizing interferometric reflectometry. But he cautions, â€śâ€ťUnambiguous observation of a subsurface ocean or liquids in the ice of Europa is only the first step towards identifying the possibility for life . . . What we are proposing will not be able to tell us whether there are living organisms in Europa, but it could provide strong evidence for that possibility.â€ť