Jupiter’s moon Europa might glow in the dead of night. Lab experiments have proven that the kind of ice that covers the moon’s floor glows beneath radiation, which might assist us work out the composition of its frozen plains and subsurface oceans.
Due to the way in which Jupiter’s powerful magnetic field accelerates charged particles, Europa is continually bombarded by high-energy electrons. Murthy Gudipati at NASA’s Jet Propulsion Laboratory in California and his colleagues investigated how Europa’s icy floor would possibly react to that bombardment by blasting electrons at samples of ice enriched with molecules which may be discovered on Europa.
When the electrons hit molecules within the ice, the molecules fell aside and their constituent atoms absorbed some power. The atoms then re-emitted that power as mild, inflicting an eerie, green-tinged glow. This was brighter or dimmer relying on the kind of molecule – for instance, including sodium chloride decreased the glow.
“For those who think about that you’re standing on Europa and looking out on the glow beneath your ft, the brightness could be much like if you happen to have been to face exterior beneath full moonlight after which have a look at the bottom,” says Gudipati. “However Europa’s floor is a really harmful surroundings, so whereas we are able to think about standing on it, a couple of seconds standing on Europa would in all probability kill an individual.”
Though visiting Europa in particular person could also be a non-starter, NASA already has a spacecraft within the works, the Europa Clipper mission that’s deliberate to launch in 2024 and research the moon whereas orbiting Jupiter. It might doubtlessly observe the glowing ice and use its brightness to assist determine its composition.
“There’s some proof that there are oceans beneath the ice on Europa which may very well be liveable, and if that’s the case, the minerals and salts which can be in that ocean must be exchanging with the floor,” says Gudipati. Determining what the surface is manufactured from might assist us perceive whether or not Europa’s seas have the required components for all times.
Journal reference: Nature Astronomy, DOI: 10.1038/s41550-020-01248-1
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