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Jupiter's Moon Io Has a Volcanic Sub-Surface
gabbo529 writes "NASA scientists have discovered new information on one of Jupiter's moons, indicating it has a molten magma sub-surface (abstract). This discovery, made using data analysis from NASA's Galileo spacecraft, reveals why that particular moon is the most volcanic object known in the solar system. The moon, which is named Io, produces about 100 times more lava each year than all the volcanoes on Earth combined. The global magma ocean about 30 to 50 kilometers (20 to 30 miles) beneath Io's surface explains the moon's activity."
Science has a nice graphic, too.
They certainly didn't know that the solid surface is floating in a more-or-less continuous magma lake in the 70's.
...and has been in the planet's atmosphere since 2003.
That's a really interesting way of looking at it.
It's been widely known for a long time that Io is volcanically active. I remember reading about it in a kids' astronomy book in the 1970's.
People have known for a long time that Io has volcanic activity but no one new before now that Io has a sub-surface made entirely of magma.
The main theory of how the planet Earth evolved was that the land was formed from a magma sub-surface that cooled and gave us what we have today. Ergo Io may be a window into the Earth's development.
"Maybe this world is another planet's hell"
Aldous Huxley
How many Slashdot readers don't know that Io is the most volcanically active body in the solar system?
I just thought it was kinda frustrating reaching Io at the end of the description. I was hoping it was another of Jupiter's moons because I figured if it were Io, Io would've been stated.
Viable Slashdot alternatives: https://pipedot.org/ and http://soylentnews.org/
"Whether they ever find life there or not, I think Jupiter should be considered an enemy planet." - Jack Handy
Earth doesn't need fixing. The problem is the stupid damn monkeys who live there.
Confucius say, "Find worm in apple - bad. Find half a worm - worse."
So we shouldn't attempt any landings there either?
Confucius say, "Find worm in apple - bad. Find half a worm - worse."
From the article: "Scientists are excited we finally understand where Io's magma is coming from and have an explanation for some of the mysterious signatures we saw in some of the Galileo's magnetic field data," Krishan Khurana, lead author of the study and former co-investigator on Galileo's magnetometer team at UCLA, said.
Amazing what slashdot ACs know before anyone else does. Maybe he can tell us what New Horizons will find when it gets to Pluto and save us the wait.
I think some of the people confidently commenting on this article have a geology knowledge level akin to "I think it's made of rock."
I thought it was a pretty interesting result. They'd been guessing beforehand. Now they have actual evidence of a global magma layer.
A magma ocean is not a 100% liquid rock layer beneath the surface.
The observations made by this team are consistent with a 50 km-thick layer about 50 km below the surface (that is, within the mantle) with >=20 volume% melt fraction. This work is based on how Io affects Jupiter's magnetic field.
Other research teams have demonstrated, since the 1990s that Io should have a mantle with a >= 20 volume% melt fraction at some depth in the mantle--it was never clear where this magma ocean was located. This work is based on observations of the surface eruptions and models for how quickly silicate lavas cool.
The fact that these agree is significant.
A substantial portion of Io at 100 volume% melt would actually not work because pure liquid does not dissipate enough of the energy from the tidal forces to maintain 100 volume% melt. That is there's a feedback loop between Io's interior and the tidal flexing:
* Too much liquid in the interior and the energy dissipation will decrease significantly, allowing the liquid to cool enough to solidify significantly.
* Too little liquid and the interior would quickly dissipate enough tidal energy (in the form of friction) to significantly melt the interior.
So, Io's orbital resonances keep a small part of its mantle molten at between 20 volume% and 50-70 volume.
That there's now a depth associated with this magma ocean is actually quite significant. We can start better understanding the role volatiles play in Io's volcanism now that we know where the molten rock is coming from.