Friday, March 21, 2014

Europa Recreated

Europa, discovered in 1610 by Galileo Galilei, is the sixth-largest moon in the Solar System. It has an extremely thin atmosphere primarily composed of oxygen and a surface of smooth water ice. The geological structures observed during a space mission by the two Voyager probes suggest there is an upwelling of fluids coming from the inside, as well a composition of volatile compounds like carbon dioxide, sulfur dioxide, and hydrogen peroxide. Scientists believe that beneath Europa’s icy crust, a large ocean made up of water, salts, and gases could exist. If a reservoir of liquid water exists inside Europa, scientists believe there could be life.

Victoria Munoz Iglesias proposed, “Just like Earth’s magma emerges to the surface, a similar phenomenon could occur in Europa. Although, in this case it would be a watery cryomagma that would evolve and emerge outwards from the interior of the icy moon.” To test this hypothesis, Munoz's team simulated an experiment in the laboratory, replicating the extreme conditions in the moon’s crust. Scientists examined pressures up to 300 times that of the Earth's atmosphere at temperatures near zero degrees Celsius.

The scientists waited to see what would happen to an aqueous solution of carbon dioxide and magnesium sulfate in these extreme conditions when it emerged and cooled on the surface. Depending on the fluid’s evolution, three types of minerals were formed inside of the crust including water ice, clathrates (chemical substances consisting of lattices that trap or contain molecules) of carbon dioxide and very hydrated magnesium sulfates. Each of these processes act to change the volume of the upwelling cryomagma and thus to deform Europa's crust. If the quantity of clathrates is less than the quantity of hydrated salts when the process is over, the volume increases making visible topographical features in the crust. On the other hand, if there is a greater quantity of clathrates than the quantity of hydrated salts, or if the process is destroyed, the volume decreases causing depressions in the crust. This is consistent with the seemingly chaotic nature of Europa's terrain.

However, Jupiter and its other moons affect the appearance of the surface in a way not replicated in the lab. Among the theories of why the Europa had a reddish color, the two most viable are that the color is a result of strong irradiation from charged particles in Jupiter's magnetosphere and that the color results from the bombardment of volcanic sulfurous compounds from other moons such as Io.

The Munoz experiment supports the hypothesis that a saline aqueous medium, capable of hosting life, can replicate observed characteristics of Europa's surface, thus reinforcing the need for a space mission to Europa. President Barack Obama has presented NASA with fifteen million dollars to search for signs of life on Europa for the next ten years. In addition, the European Space Agency has also planned to launch the Jupiter Icy Moons Explorer Mission in 2022. When this spacecraft arrives at Jupiter’s moons, it will fly over Europa two times to measure the thickness of its crust and explore its habitability. A mission to Europa is crucial in expanding our knowledge about the moon's crust and making new discoveries to see if it is capable of fostering life.
Clara Lee