Jupiter's ocean moon Europa probably glows in the dark:
The icy Jupiter moon Europa is an astrobiological beacon, quite literally glowing in the deep darkness far from the sun, a new study suggests.
Jupiter's intense radiation environment likely lights up Europa's icy shell, which overlies a huge, potentially habitable ocean of salty liquid water, researchers have found.
"If Europa weren't under this radiation, it would look the way our moon looks to us — dark on the shadowed side," study lead author Murthy Gudipati, a scientist at NASA's Jet Propulsion Laboratory (JPL) in Southern California, said in a statement. "But because it's bombarded by the radiation from Jupiter, it glows in the dark."
[...] "But we never imagined that we would see what we ended up seeing," study co-author Bryana Henderson, also of JPL, said in the same statement. "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."
This nightside glow — it won't be visible on Europa's sun-illuminated dayside — has more than just gee-whiz appeal. Its color and intensity could reveal key details about the composition of the moon's icy shell, study team members said.
Related Stories
Europa volcanism & interior heating modeled in detail, offers research targets for upcoming missions
Europa, an icy Jovian moon that likely possesses an ocean beneath its icy crust, may have an interior that is hot enough to produce volcanic activity on its seafloor. New research provides evidence that this seafloor volcanism likely occurred in the moon's past and [may be] ongoing at present as well.
The team of researchers, led by Dr. Marie Běhounková of Charles University in the Czech Republic, developed their own 3D models of Europa's interior and heating transfer properties to investigate the possibility of volcanism on Europa's ocean floor given other volcanism seen in the Jovian system.
[...] These volcanoes would form due to the melting of Europa's interior and heat transfer from the rocky interior of Europa to the seafloor. Models developed by Běhounková et al. show that many different factors — including radiogenic power and tidal forces — contribute to the melting of the icy moon's interior.
[...] A Laplace resonance is a phenomenon that occurs when three planetary bodies with an orbital period ratio of 1:2:4 exert regular and periodic gravitational effects on each other. These nudges create tidal forces that translate to the heating of the body's interior.
It's that interaction that led Běhounková et al.'s research toward the conclusion that this resonance and the associate tidal forces can cause increased periods of volcanic activity — called magmatic pulses — on Europa.
Journal Reference:
Marie Běhounková, Gabriel Tobie, Gaël Choblet, et al. Tidally Induced Magmatic Pulses on the Oceanic Floor of Jupiter's Moon Europa, Geophysical Research Letters (DOI: 10.1029/2020GL090077)
Previously: Hydrogen Emitted by Enceladus, More Evidence of Plumes at Europa
Plate Tectonics on Europa and Subsurface Oceans in the Outer Solar System
NASA Finds Evidence of Water Plume on Europa
Europa Plume Sites Lack Expected Heat Signatures
Jupiter's Watery Moon, Europa, Is Covered in Table Salt
Jupiter's Ocean Moon Europa Probably Glows in the Dark
(Score: 2, Touché) by Runaway1956 on Monday November 16 2020, @08:04PM
Chernobyl had some far reaching effects!
(Score: 0) by Anonymous Coward on Tuesday November 17 2020, @03:02AM
Literally :)
CYA
(Score: 2) by PiMuNu on Tuesday November 17 2020, @09:51AM (3 children)
> The icy Jupiter moon Europa is an astrobiological beacon, quite literally glowing in the deep darkness far from the sun, a new study suggests.
Just to save you from clicking, no, there is no light detected, this is just theoretical (until Europa Clipper arrives). Bombard ice with electrons and the ice glows thanks to some sort of stimulated emission (excitation of the molecular electrons? The journal article is vague). The claim is that this would be bright compared to the background from the Jovian aurora.
Presumably few MeV electrons discussed in the article would not penetrate very deep into the ice (maybe a few cm), so this would only really tell us about the surface not anything inside the moon. Perhaps there might be some residual from e.g. high energy muons penetrating deep but I can't imagine this would make much light.
(Score: 2) by Muad'Dave on Tuesday November 17 2020, @01:26PM
If nothing else you'll get Cherenkov radiation [wikipedia.org] if the particles are energetic enough. They've fiddled with this [arxiv.org] in the Antarctic. This [wisc.edu] is an interesting lecture slide deck.
(Score: 2) by Muad'Dave on Tuesday November 17 2020, @01:33PM (1 child)
PS to my other post - this paper [arxiv.org] quantifies the energy thresholds:
(Score: 2) by PiMuNu on Tuesday November 17 2020, @02:46PM
That was my first thought - but they don't mention it in the (Nature Comms) article.