Jupiter’s moon Io may have a hellish magma ocean below its surface

There are more than 200 moons in the solar system, but none like Io, the third largest moon in Jupiter’s eighty moons. Io is really volcanic. In fact, it’s dotted with hundreds of powerful active volcanoes beneath whose crust there must be something extraordinary.

That thing could be a thick layer of molten rock at the level of the moon, or an “underground ocean of magma,” according to a new study by Yoshinori Miyazaki and David Stephenson, planetary scientists at Caltech.

This potentially superheated sea of ​​molten rock, unique in the solar system, could hold secrets, strange mechanisms for forming moons and planets, and even recipes for strange extraterrestrial life. Only closer examination of the 2,200-mile-diameter moon will tell.

Miyazaki and Stevenson weren’t the first scientists to guess what lurks beneath Io’s potential 20-mile-thick crust. It has been the subject of heated debate for years. But their new peer-reviewed study of the moon’s mantle may be the most comprehensive yet.

A volcanic eruption on Io, Jupiter’s third largest moon, captured by NASA’s New Horizons spacecraft.

To look below Io’s surface, Miyazaki and Stevenson combed through reams of NASA data. Galilean probe that orbited Jupiter for eight years beginning in 1995. Initial analysis of the probe’s magnetic data led to a widespread consensus that Io’s mantle, the layer beneath the lunar crust, includes an upper layer 30 miles across. thickness that must be “cast or partially”. molten.” “,” According to NASA.

Compare this to Earth’s mantle, as well as the mantle of all the other planetary bodies in the solar system, which is mostly solid and composed mostly of ice or superheated rock. In general, planetary scientists who read the Galileo data assumed that Io has an underground magma ocean or some kind of rocky, sponge-like outer mantle submerged in magma.

A new look at the data led by Miyazaki and Stephenson concludes that it is the molten sea. They based their conclusion on estimates of mantle temperatures through analysis of Io’s volcanoes, which can spew magma hundreds of miles into the moon’s sulfur dioxide atmosphere. The upper part of the mantle can reach temperatures of 2800 degrees Fahrenheit.

That’s hot. But not hot enough to preserve the soft interior. The analysis is complex, but it boils down to this: Like a pot of gravy on the stove, Io will need a lot of heat to stay constantly fluffy on the top mantle. Without it getting Hot enough, the broth, the spongy rock, will separate: rock at the bottom and magma at the top.

Crunching the numbers, Miyazaki and Stephenson calculated the heat of Io’s core, as well as the effects of its strange and steep orbit, which eats away at the mantle, spreads heat around it and prevents Io from cooling permanently.

They concluded that the sauce would separate. “The amount of internal heating is insufficient to maintain a high melting point,” they wrote. Hence what they believe could be the highest magma ocean.

Fortunately, we’ll know more soon. NASA’s Juno probe, which arrived around Jupiter in 2016, is scheduled to take readings of Io in 2023 and 2024, specifically measuring the “love number,” a measure of the planet’s toughness or lack thereof. “If a large amount of love is found, we can say with more certainty that a magma ocean exists below the surface of Io,” Miyazaki told The Daily Beast.

We already knew Io was weird. It’s possible even rarer – And this weirdness could have implications for rocket science. “I don’t think it will change the understanding of planetary formation significantly, but it does change the way we look at the internal structure and thermal evolution of hot objects like Io,” said David Grinspoon, principal scientist at the Institute for Planetary Sciences based in Arizona.

Astrobiologists lurk in the academic shadows. Experts on how and where life might have evolved in the universe. If there is alien life somewhere and it looks like life on Earth, we should expect to find it, or evidence of its extinction, on planets and moons that had or had Earth-like environments. Mars. Venus. called Saturn’s moon Enceladus.

But volcanoes, with their extreme energy transfers, are widely considered essential components of a living ecosystem. So planets and moons with lots of volcanoes are great places to look for ET in theory, that should include Io.

However, I too much volcanoes. So if there is life evolving there, it’s probably very strange life. He really loves the heat. “Lava tubes can create a favorable condition for microbes,” Miyazaki said.

The question, for astrobiologists, is whether a magma ocean would create more or fewer lava tubes than a magma sponge. “I don’t have an honest answer,” Miyazaki said. “But it’s interesting to think about such implications.”