If our Moon gives off 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 further information on 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 astrophysicist Murthy Gudipati of NASA’s Jet Propulsion Laboratory (JLP) and lead author of the study, now published in Nature Astronomy.
Europa is a frozen ocean world, orbiting Jupiter and suffering from all the considerable forces emanating from the gas giant, including the high-energy radiation (such as electrons and other particles) that the planet emits. It is what makes the satellite glow in the dark when the particles reach its surface.
In addition to being probably a spectacle, brightness also has a practical application: highlighting the composition of the ice on the satellite’s surface. Last year, planetary scientists from JLP and the California Institute of Technology (Caltech) discovered, using the spectral analysis of visible light, that the yellow color visible on parts of the European surface is actually sodium chloride, the popular salt cuisine, present in the terrestrial oceans.