Jupiter's Moon Io Might Have a Hellish Magma Ocean Beneath Its Surface - The Daily Beast

There are much than 200 moons successful the star system, but nary rather similar Io, the 3rd largest of Jupiter’s 80 moons. Io is really, truly volcanic. In fact, it’s peppered with truthful galore hundreds of almighty progressive volcanoes that determination indispensable beryllium thing antithetic beneath its crust.

That thing could beryllium a heavy moonwide furniture of molten rock—or a “subsurface magma ocean,” according to a caller survey published successful the Planetary Science Journal connected Nov. 16 from Yoshinori Miyazaki and David Stevenson, planetary scientists astatine the California Institute of Technology.

That imaginable super-hot oversea of melted rock—which is unsocial successful the star system—could harbor secrets, weird mechanisms for forming moons and planets, and adjacent recipes for exotic alien life. Only further scrutiny of the 2,200-mile-diameter satellite volition tell.

Miyazaki and Stevenson aren’t the archetypal scientists to marque an educated conjecture astatine what lies beneath Io’s perchance 20-mile-thick rocky crust. It’s been the taxable of heated statement for years. But their caller peer-reviewed survey of the moon’s mantle mightiness beryllium the astir thorough yet.

A volcanic detonation connected Io, Jupiter's 3rd largest moon, arsenic captured by NASA's New Horizon spacecraft.

NASA/JPL/University of Arizona

To adjacent beneath Io’s surface, Miyazaki and Stevenson revisited reams of information from NASA’s Galileo probe, which orbited Jupiter for 8 years starting successful 1995. Initial investigation of the probe’s magnetic information led to a escaped statement that Io’s mantle—the furniture nether the moon’s crust—includes a 30-mile heavy apical furniture that should beryllium “molten oregon partially molten,” according to NASA.

Compare this to Earth’s ain mantle, arsenic good arsenic the mantles of each different planetary assemblage successful the star system, which are mostly coagulated and dwell mostly of crystal oregon superheated rocks. Broadly speaking, planetary scientists speechmaking the Galileo information assumed Io either has an underground magma water oregon a benignant of sponge-like rocky outer mantle soaked successful magma.

A caller look astatine the information led Miyazaki and Stevenson concludes it’s the molten sea. They based their decision connected estimates of the mantle’s somesthesia via investigation of Io’s volcanoes, which tin spew magma hundreds of miles into the moon’s sulfur dioxide atmosphere. The apical of the mantle mightiness registry arsenic blistery arsenic 2,800 degrees Fahrenheit.

That’s hot. But not blistery capable to prolong a spongy interior. The investigation is complicated, but it boils down to this: Like a cookware of gravy connected a stovetop, Io would request a batch of vigor to enactment consistently spongy successful its precocious mantle. Without capable heat, the gravy—er, the spongy rock—would separate: stone connected bottom, magma connected top.

Miyazaki and Stevenson crunched the numbers, calculating the vigor from Io’s halfway arsenic good arsenic the effects of its weird, highly-elliptical orbit, which sloshes the mantle, spreads vigor around, and keeps Io from ever permanently cooling.

They concluded that the gravy would separate. “The magnitude of interior heating is insufficient to support a precocious grade of melting,” they wrote. Hence what they judge could beryllium a topmost magma ocean.

Luckily, we’ll cognize much soon. NASA’s Juno probe, which arrived astir Jupiter successful 2016, is scheduled to instrumentality readings of Io successful 2023 and 2024—specifically measuring the “Love number,” a gauge of a planet’s rigidity oregon deficiency thereof. “If a ample Love fig is found, we tin accidental with much certainty that a magma water exists beneath Io’s surface,” Miyazaki told The Daily Beast.

We already knew Io is weird. It’s imaginable it’s adjacent weirder—and that weirdness could person implications crossed the abstraction sciences. “I don’t deliberation it greatly changes knowing of planetary formation, but it does alteration however we presumption the interior operation and thermal improvement of tidally heated bodies similar Io,” David Grinspoon, a elder idiosyncratic with the Arizona-based Planetary Science Institute, told The Daily Beast.

Io and Europa, Jupiter's 2 largest moons, captured by NASA's Juno spacecraft.

NASA/JPL-Caltech/SwRI/MSSS/Roman Tkachenko

Lurking successful the world shadows are the astrobiologists. The experts successful however and wherever beingness could germinate successful the universe. If there’s extraterrestrial beingness retired determination determination and it looks similar Earth life, we should expect to find it—or grounds of its extinction—on planets and moons that have, oregon had, Earthlike environments. Mars. Venus. A satellite of Saturn called Enceladus.

But volcanoes with their utmost transfers of vigor are wide considered cardinal components of a surviving ecosystem. So planets and moons with tons of volcanoes are large places to look for E.T. In theory, that should see Io.

However, Io mightiness have excessively many volcanoes. So if there’s beingness evolving there, it’s astir apt precise unusual beingness that really likes heat. “Lava tubes could beryllium creating a information favorable for microbes,” Miyazaki said.

The question, for astrobiologists, is whether a magma water would make much oregon less lava tubes than a magma sponge. “I don’t person an explicit answer,” Miyazaki said. “But it’s absorbing to deliberation astir specified implications.”

Dirk Schulze-Makuch, an astrobiologist astatine the Technical University Berlin, has agelong advocated a thorough hunt for beingness connected Io. A magma water would lone spoil that hunt if it were truly adjacent to the surface. A bully heavy crust should insulate the outermost regions of the satellite from scouring heat, and sphere the imaginable for evolution. “There seems to beryllium rather a spot of crust,” Schulze-Makuch told The Daily Beast.

If anything, the anticipation of a magma water connected Io conscionable underscores however absorbing and breathtaking the satellite is—and wherefore it should beryllium a apical people for aboriginal abstraction probes, Schulze-Makuch said. “Io is simply a unsocial benignant of moon, precise dynamic, and we should not disregard it altogether.”