If our Moon emanates a warm glow on its sunlit surface, an experiment that recreated the atmosphere of one of Jupiter’s icy moons ended up showing that Europa shines incessantly in the darkness of space.
“This nocturnal glow in the ice could provide additional information about the composition of Europa’s surface, and the variation in this composition, in turn, would give us clues as to whether it has adequate conditions to sustain life,” said researcher astrophysicist Murthy Gudipati from NASA’s Jet Propulsion Laboratory (JLP) and lead author of the study, now published in Nature Astronomy.
Europa is a frozen, oceanic world, orbiting Jupiter and suffering all the considerable forces emanating from the gas giant – among them, the high-energy radiation (such as electrons and other particles) that the planet emits. It is what makes the satellite glow in the dark, as the particles reach its surface.
In addition to probably being a spectacle, the brightness also has a practical application: pointing out the composition of the ice on the surface of the satellite. Last year, planetary scientists from JLP and the California Institute of Technology (Caltech) discovered, using spectral analysis of visible light, that the yellow color visible on parts of Europe’s surface is actually sodium chloride – the popular salt kitchen, present in the Earth’s oceans.