JUPITER’S MOON EUROPA COULD GLOW IN THE DARK

Raisumai Basumatary

BSc 1^st Sem (Physics Major)

Ice on the night side surface of Jupiter’s moon Europa could emit a unique glow. According to US-based scientists Murthy Gudipati and Bryana Henderson at NASA’s jet propulsion Laboratory and Fred Bateman at the Nation Institute of Standards and Technology. The researchers did lab-based experiments that suggest that the ice emits visible light as a result of being bombarded by high energy particles. Their research provides important information for NASA’s upcoming Europa Clipper mission which could offer an unprecedented glimpse of the composition of Europa’s subsurface ocean. Europa is Jupiter’s fourth largest moon and as it passes through the strong magnetic field of its host planet, its surface is bombarded by high energy photons ,electrons, and ions. As these particles interact with the moon’s salt and ice rich crust, they could trigger complex physical and chemical processes that have important consequences for Europa’s chemical composition.

On geological timescales, the energy rich product of these reactions could be transported through Europa’s crust, before entering the vast ocean of liquid water beneath. By tidal forces, this ocean is one of the most promising candidate locations for extraterrestrial life in the solar system.

High Energy Electrons:

In their study, the bio fired high energy electrons at water ice containing different types of salt and analysed the light emitted by their samples. They discovered that the samples emitted characteristic light spectra at visible wavelengths. They also found that emission was enhanced in ice containing magnesium-sulphate based epsomite, and that ice containing sodium chloride and sodium carbonate gives off much less light. On Europa’s surface, this light emission would create a unique night time glow, not likely to be found elsewhere in the solar system.

By mapping variations in this glow on Europa’s surface, the bio believe that scientists could determine what salts are present within Europa’s ice. While dark regions could indicate the presence of sodium and chloride rich surfaces, while brighter areas may give away magnesium and sulphate dominated surface. With observations of Europa’s day time side would then enable astronomers to identify specific geological features by their chemical compositions.

Gudipati and their colleagues now hope that through future missions spacecraft flying low over Europa’s night side surface could observe this light directly. This will soon be possible through visible instruments aboard NASA’s Europa Clipper Mission, which due for launch in 2025. These observations could be the key to determining whether life could exist beneath Europa’s surface, and may also pave the way for analysis of other Jovian moons subjected to particle bombardment, including lo and Ganymede.