NASA says Jupiter’s funky moon Europa could glow in the dark

If you manage to get to Jupiter and then look at the dark side of its moon Europa, you could be blown away by an ethereal glimmer. The fascinating icy moon can show off a bright night side in the dark triggered by explosive radiation.

Scientists at NASA’s Jet Propulsion Laboratory have discovered what the glow of Europa might look like and how it binds to the composition of lunar ice. The team published an article on the potential glow in the journal Nature Astronomy on Monday.

Here on Earth, we are used to seeing our moon shine on us as sunlight reflects off its surface. This is not how the special glow of Europa would work. The ice of Europe is likely mixed with salts (which we know as Epsom salt and table salt). Mix in some high-energy radiation expelled by Jupiter and you’ll get a lovely glow-in-the-dark effect.

“If Europa weren’t under this radiation, it would have the appearance of our moon to us – dark on the shadow side,” said Murthy Gudipati of JPL, lead author of the study. “But since it is bombarded with radiation from Jupiter, it glows in the dark.”

To delve into these ideas, the JPL researchers built a special instrument with an incredible name: Ice Chamber for Europe’s High-Energy Electron and Radiation Environment Testing (Ice-Heart). Experiments conducted with Ice-Heart mimicked the conditions on Europa and showed how various ice and salt compositions generated distinct glows.

“Different saline compounds react differently to radiation and emit their own unique glimmer,” NASA said in a statement Monday. “To the naked eye, this glow sometimes appears slightly green, sometimes slightly blue or white, and with varying degrees of brightness, depending on the material.”

Europe probably hosts an ocean hidden under the ice. This is one of the reasons why scientists think it could be a great place to look for signs of alien life, and also why NASA is sending his Europa Clipper spacecraft mission to see more closely.

NASA aims to launch the Europa Clipper in the mid-2020s. The spacecraft will make close passes of the moon, but it will not physically dive into ice or the inner ocean to look for microbes. It could still tell us a lot about Europa’s potential for habitability.

This research could help scientists make sense of the data sent by Europa Clipper as they study the chemical composition of lunar ice. If we’re lucky, we might even get some nice images of Jupiter’s night light to go along with it.