New images of Jupiter’s moon Io capture the hellish volcanic landscape

A NASA spacecraft flew past Io, one of Jupiter’s largest moons and the most volcanically active world in our solar system. The spacecraft, the Juno orbiter, made its first flight yet across Io’s turbulent landscape snapshots returned speckled with sharp cliffs, sharp mountain peaks, lakes of collected lava and even a volcanic plume.

“I was impressed,” said Scott Bolton, a physicist at the Southwest Research Institute and principal investigator of the Juno mission. Dr. Bolton noted how “incredibly colorful” Io is – tinted in shades of orange-brown and yellow due to the presence of sulfur and flowing lava. He compared the moon to a pepperoni pizza.

Studying these features could help scientists figure out what drives Io’s volcanoes, some of which shoot lava tens of kilometers into space, and confirm that this activity comes from an ocean of magma hidden beneath the moon’s crust. Deciphering the secrets of the volcanoes could ultimately reveal the influence Jupiter has on its eruptions, which could provide a clue to how the gas giant and its satellites formed.

This is not the first time a NASA spacecraft has flown past Io. In 1979, Traveler 1 discovered that Io was volcanically active during its journey into interstellar space. Twenty years later, NASA’s Galileo mission sent what Dr. Bolton mentions ‘postage stamps’, or close-ups of specific features on Io’s surface.

Juno carried out a number of them remote observations of Io in recent years. The last flyby took place on December 30, when the spacecraft came within 1,500 kilometers of the moon. The images taken during this visit were taken with an instrument called JunoCam and are in visible wavelengths. They are some of the highest resolution views of Io’s global structure. The mission’s managers shared six images of Io on the mission websiteand members of the public have since uploaded digitally enhanced versions that highlight features on Io’s surface.

Dr. Bolton said he was struck by the sharpness of the edges of some of the mountains in the images, which made him wonder how they are formed and what it would be like to visit such a place.

“I wonder what it’s like to hike there,” he said, “or to snowboard from that peak.”

Mission scientists are already analyzing these images, looking for differences across Io’s surface to learn how often the volcanoes erupt, how bright and hot those eruptions are, and how the resulting lava flows. According to Dr. Bolton, the team will also compare Juno’s images with older images of Jupiter’s moon to determine what has changed during different encounters on Io.

And they’ll have a second set of data to work with in a month, when Juno completes another short flyby of the explosive world on February 3.