According to new research, Jupiter’s moon Europa may glow in the dark. The glow would be caused by Jupiter’s high-energy radiation hitting Europa’s ice-filled surface.
Scientists at NASA’s Jet Propulsion Laboratory (JPL) in California conducted new research in order to find out how the glow would appear as well as the composition of the moon’s ice-filled surface. NASA has already confirmed salt compounds on Europa and with those combined with the water ice they would all react uniquely to the radiation as they release their own glows. Based on which compounds were reacting to the radiation, they could glow green, blue, or even white.
The research team recreated conditions similar to the surface of Europa and they created a piece of equipment called Ice Chamber for Europa's High-Energy Electron and Radiation Environment Testing (or ICE-HEART) to see how the organic materials underneath the moon’s ice would react to radiation.
Murthy Gudipati from JPL and who is the lead author of the study explained their research further, “We were able to predict that this nightside ice glow could provide additional information on Europa's surface composition. How that composition varies could give us clues about whether Europa harbors conditions suitable for life,” adding, “If Europa weren't under this radiation, it would look the way our moon looks to us - dark on the shadowed side.” “But because it's bombarded by the radiation from Jupiter, it glows in the dark.”
JPL’s Bryana Henderson who co-authored the study, weighed in by stating, “But we never imagined that we would see what we ended up seeing.” “When we tried new ice compositions, the glow looked different. And we all just stared at it for a while and then said, ‘This is new, right? This is definitely a different glow?’ So we pointed a spectrometer at it, and each type of ice had a different spectrum.”
The predicted glow will hopefully be seen and recorded when the Europa Clipper spacecraft flies by the moon while studying Jupiter. While it orbits Jupiter, the spacecraft will pass by Europa approximately 45 times with each flyby taking a different route so that almost the entire moon can be scanned and studied.
“It's not often that you're in a lab and say, ‘We might find this when we get there,’” Gudipati stated. “Usually it's the other way around - you go there and find something and try to explain it in the lab. But our prediction goes back to a simple observation, and that's what science is about.”
The spacecraft is scheduled to be launched sometime in the 2020s so we’ll have to wait a little while longer to hopefully see the glow. Until then, an illustration of what Europa’s nightside may look like while glowing can be seen here.
As for their study, it was published in Nature Astronomy where it can be read in full.