Vinsamlegast notið þetta auðkenni þegar þið vitnið til verksins eða tengið í það: http://hdl.handle.net/1946/5351
Evidence for a subsurface ocean on Europa
Europa is one of the four Galilean satellites orbiting Jupiter. It was discovered by in 1610 and has since intrigued scientists and amateurs alike. Its location in the outer solar system permits water ice to exist in abundant form and beneath the icy shell of Europa scientists believe water to exist in liquid form. The formation of ridges, cycloids and other linear features crisscrossing the surface suggest the presence of a liquid water layer underlying the crust. Calculations of the magnitude of tidal stress needed to break the frozen surface show that sufficient stress to overcome the strength of the crust is only attained if a liquid layer is present under the moon's ice cover. The strongest evidence comes from measurements of the magnetic field around Europa. The results require a conductive layer of liquid water with dissolved salts underlying the ice crust at shallow depths. The presence of liquid water makes Europa one of the few places in our solar system that could harbour life. To confirm or refute this the National Aeronautics and Space Administration (NASA) and the European Space Agency (ESA) have joined forces to send two spacecrafts to the Jupiter system. The two crafts are scheduled for two seperate launches in 2020 arriving at the Jupiter system in 2025.