Io: The Most Volcanically Active Body in Our Solar System
Io, one of the four Galilean moons of Jupiter, exhibits over 400 active volcanoes, making it the most volcanically active celestial body in the solar system. The volcanic eruptions primarily eject sulfur dioxide, which not only creates a unique atmosphere around the moon but also largely spreads into outer space.
What Fuels Io’s Volcanic Activity?
One might wonder exactly why Io is such a hotspot for volcanic activity. The answer lies with Jupiter. The massive gravitational pull exerted by the gas giant on Io generates substantial friction and heat within the moon. Furthermore, the gravitational interactions with other big moons like Ganymede and Europa also contribute to the heating of Io’s interior, leading to the formation of surface volcanoes.
A Crisp Mosaic of Io
This week’s space photo is a crystal-clear mosaic, composed of several images captured by the Galileo spacecraft. During its flight on July 3, 1999, the spacecraft was nearly 130,000 kilometers above Io’s rugged surface. The colours in the photo represent what humans would see if we visited the moon. The picture presents with fine details visible to a scale of three kilometers, including the volcanic activity.
Volcanic Features on Io’s Surface
The photograph also features yellow, white, and orange spots. These colorations signify frozen sulfur dioxide ice coated with a layer of volcanic dust. The most significant volcano on Io is Loki Patera. This volcano, with a diameter of 202 kilometers, is the most thermogenic in the entire solar system, even more so than all our planet’s volcanoes combined. Loki’s eruptions are near-annual and are visible from the Earth’s surface.
The Mystery of Io’s Dunes
Io continues to intrigue scientists to this day. Recently, researchers found what probably seem to be dunes on Io. This discovery has left scientists puzzled because the winds on the moon, though high-speed at 1000 kilometers per hour, are significantly weaker, almost 100,000 times weaker than that of Earth’s. It meant that the dunes on Io are formed not by wind but by lava flows vaporising subsurface snow.
Life on Jupiter’s Moons?
For the time being, there are no imminent plans for a mission to Io. However, NASA plans to send a spacecraft to another of Jupiter’s moons, Europa, sometime around 2030. The proposed Europa Clipper mission aims at making dozens of flybys of Europa to gather more information about the ocean concealed under its thick icy crust. Speaking about the mission’s potential, researcher Robert Pappalardo mentioned, “Predictions of a hot, rocky inner core and submarine volcanoes on Europa increase the likelihood that its extensive ocean is habitable.” This opens a thrilling chapter in the quest for extraterrestrial life.
