Is There Life on Io?

It is highly unlikely that life as we know it could survive on Io due to extreme atmospheric and surface activities.

Dec 23, 2022

8 min read

home, Astronomy 🔭, Solar System, Jupiter's Moons

While their work might appear to have delivered more questions than answers, it highlights many ways that a better understanding of one of Jupiter's largest moons could help to solve mysteries about the Earth and other geologically active bodies. Understanding the effects of Io's heat source could shed light into the depths of watery worlds such as Enceladus. With so much volcano-like complexity to untangle, the lead researcher on this research, Catherine de Kleer, a planetary scientist at MIT, turned to the Keck and Gemini observatories on top of Mauna Kea, Hawaii, hoping to get an accurate snapshot of how the behavior of one of Jupiters largest moons have changed over time.

Even though it is about 4.5 billion years old, the vast amount of lava production means Ios solid surface is not much older than a couple of million years, added Alfred MacEwen, a planetary geologist at the University of Arizona. One of the largest Jovian moons, the volatile, transient atmosphere is too thin to hold much heat, which is why the average temperature on Io's surface is -202degF. Although the moon's volcanic-covered image suggests that Io, the third largest Jovian moon, will be a warm body, its frigid surface is consistently frigid, with an estimated negative 230degF.

When Jupiter's third-largest moon Io passes in Jupiter's shadow and is not exposed to direct sunlight, it is too cold for the gas sulfur dioxide, which condenses on the Ios surface. The tugging from Jupiter, Ganymede, and Europa warms the interior of Jupiter's third-largest moon Io, creating volcanoes that emit warm sulfur dioxide gas. As byproducts of Ios volcanism, sulfur, sulfur dioxide gas, and silicate pyroclastic materials (such as ash) are blasted as far outward as 200 km (120 mi), producing large umbrella-shaped plumes, painting surrounding terrain in red, black, and white, and providing materials for the patchy Io atmosphere (and the vast magnetosphere) of the planet Jupiter.

During these eclipses, Io's sulfur dioxide gas drops, suggesting the moon's thin atmosphere has mostly collapsed and frozen over on its icy surface. Such activities make up a tiny fraction of the moon's immediate atmosphere, but they do ultimately freeze over and accumulate the sulfur dioxide stores. When lava flows into sulfur dioxide below its surface, the result is a rapidly moving vent, which could shift large amounts of grains around and potentially allow large-scale features like dunes to form.

The new findings could help scientists understand more of the Jovian system, where roughly half the sulfur dioxide spewed by volcanoes on Io ultimately drifts away and circles around Jovian.

They base their conclusion on estimates of mantle temperatures derived from analyses of the Io volcanoes, which can spit magma hundreds of miles into the moon's sulfur dioxide atmosphere.

The gravitational forces placed on Io by Jupiter are so strong they contribute not only to the volcanoes that spout Sulphur dioxide into the moon's tenuous atmosphere but they turn Io into something like an electrical generator. It has a non-uniform orbit around Jupiter, which increases tidal activity, and is responsible for this great amount of volcanic activity. Jupiter's third-largest moon, Io, is caught between the immense gravitational force of Jupiter and orbital tugs by Jupiter's other moons, such as Europa and Ganymede, contributing to Ios activity.

Io is caught in the gravitational tug-of-war between Jupiter and its other moons, Europa and Ganymede, which contributes to the eruptions on the celestial body. The mechanism behind the vast volcanic activity of Io is thermal heating because Io is continually being squeezed and stretched while orbiting Jupiter - Volcano World, but also being pulled around by Europa, which is orbiting slightly outside Io. The tidal heating caused by the eccentricity of the orbital eccentricity exerted on Io has made it the most volcanically active world in the Solar System, with hundreds of volcano centers and vast flows of lava.

While most likely lifeless because of the vast amount of volcanic activity at Io, the same type of tidal heating is also experienced at Europa, Jupiter's second moon, a volcanic world that is surrounded by an icy outer shell but has shown evidence for a liquid-water interior ocean within Europas deeper interior. In this regard, Ios moon-rock dunes features are not dissimilar from the cryovolcanism and tidal heating experienced by the cold bodies of the Solar System.

Unlike the Earth and the Moon, the primary source of internal heating for Io comes from tidal dissipation, not radioactive isotope decay, resulting from Ios orbital resonances with Europa and Ganymede. Combined with Jupiter's gravity, this pattern of orbital resonances produces enormous amounts of frictional heating within one of Jupiter's largest moons, eventually producing large amounts of magma, which was predicted in a 1979 paper before anyone had seen the volcanic plumes forming on the solid surface of Io.

Unlike Earth's eruption spikes and vents, Ios volcanoes are not powered by trapped heat left over from one of the Jovian large moons formations, nor the decay of naturally occurring radioactive compounds in its rocks. Although it is generally agreed that the source of the heat, as seen in many Ios volcanoes, is tidal heating due to gravitational attraction by Jupiter's planet and its moon Europa, the volcanoes are not located at locations predicted with tidal heating. The volcanoes are caused by gravitational pulling from Jupiter on one side, followed by a perfectly balanced pulling on the other side from the other two moons, Ganymede and Europa.

Volcanic activity is also very volatile[12,50]. By studying the Ios atmosphere in detail, we get the opportunity to look at the driving mechanisms and how the system reacts to them. Ios atmosphere is composed mostly of SO2, but it is also one of the gases that drive volcanic activity.

While the geological activity could, in fact, point to the possibility of a habitable subsurface ocean on either Eris or Pluto, the Jovian moon Io--discovered by Galileo in 1610--is a highly geologically active planet, far less likely to harbor alien life than most of its less geologically active neighbors. To peek under its crust, Yoshinori Miyazaki and David Stephenson revisited the stacks of data gathered by NASA's Galileo probe, which orbited Jupiter for eight years starting in 1995. Yoshinori Miyazaki and David Stevenson and David Stevenson crunched the numbers, computing the heat coming out of Io's core and calculating the effects of its strange, heavily elliptical orbit, which causes the moons mantle to be heated, spreading heat everywhere, preventing Io from ever cooling down forever.