Jupiter's Moon, Europa, May Have Earth-like Seas: New Possibility of Life

Earth isn't the only planet that has a sea. Jupiter's moon, Europa, also has a vast, subsurface ocean--and it may be just like ours.

Europa has long been accepted as one of the likeliest candidates for hosting life outside of Earth. It possesses a frozen surface of ice that covers a global ocean of water, and data collected during NASA's Galileo mission hinted that the water actually has a salinity that is similar to the oceans on Earth.

Now a new study accepted for publication in the Astronomical Journal used the Keck II Telescope and its OSIRIS spectrometer in order to come to further research Europa's seas and understand their composition. With these tools, the researchers were able to identify the presence of magnesium sulfate salt, a mineral called epsomite, on Europa's surface. The mineral could have formed by oxidation and likely originated from the ocean below.

So exactly how did they identify the mineral? The researchers mapped the distribution of pure water ice versus anything else on the surface of Europa. The spectra showed that, in fact, most of the planet possessed significant amounts of non-water ice. At low latitudes in the area with the greatest concentration of non-water ice material they found a tiny never-before-seen dip in the spectrum.

Yet the magnesium sulfate probably didn't come from the subsurface sea. Since it's only located on the side of the moon that is balsted by sulfur from Jupiter's volcanic moon, Io, the researchers believe it was generated by the irradiation of sulfur that is ejected. Yet while magnesium sulfate is off of the table, magnesium chloride salt certainly isn't. When on the surface, magnesium chloride is broken apart and forms magnesium sulfate on the side exposed to Io. If correct, this discovery could mean that the moon's seas are similar in composition to oceans on Earth, and could herald a greater possibility of life.

Although research still needs to be done when it comes to taking samples to examine the possibility of life on the icy moon, this new research allows scientists to better target what planets and moons to examine. In addition to the possibility of life, the study also may indicate that more complex minerals and elements are located on the moon.