NASA’s spacecraft is preparing for its first encounter with the most volcanic area in the solar system. On Thursday, December 15, the Juno spacecraft will pass Jupiter’s moon Io.
This maneuver will be the ninth flyby of Io by Juno in the next year and a half. Two encounters will occur at a distance of only 930 miles (1 500 km) from the moon’s surface.
Juno captured an infrared image of Io from a distance of 50,000 miles (80,000 km) on July 5. The brightest areas in the image correspond to the highest temperatures at Io, home to hundreds of volcanoes. Some of these can send lava fountains up to dozens of miles.
Juno’s observations will be used by scientists to gain more information about Io’s network of volcanoes, and its interactions with Jupiter. Jupiter’s enormous gravitational pull tugs the moon constantly.
“The Juno extended mission will include the study of Jupiter’s moons. This is a great opportunity for our team. We have been able to obtain a wealth of new information with each close flyby,” Scott Bolton (Juno principal investigator at Southwest Research Institute in San Antonio) said in a statement.
“Juno sensors were designed to study Jupiter. But, we have been amazed at how well they can do double duty and observe Jupiter’s moons.”
On September 29, the spacecraft captured a new image showing Jupiter’s northernmost Cyclone. Jupiter’s atmosphere is dominated by hundreds of cyclones and many clusters at its poles.
Since 2016, the Juno spacecraft has been orbiting Jupiter to learn more about the giant planet. During the extended portion of its mission, which began last January and will continue through 2025, it is focusing on flybys of Jupiter’s moons.
Juno, which flew past Jupiter’s moon Ganymede in 2021, was followed by Europa this year. The spacecraft used its instruments for a look under the icy crusts of both moons. It also collected data about Europa’s interior. This is where it is believed to have found a salty ocean.
Europa’s surface is made up of ice shells that are between 10 and 15 mi (16 and 24 km) thick. The ocean that it sits on is likely to be 40 to 100 miles (64 to 161 km) deep.
Juno’s data and images could be used to inform two separate missions that will visit Jupiter’s moons over the next two years: NASA’s Europa Clipper mission and the European Space Agency’s Jupiter Icy Moons Explorer mission.
The first spacecraft, which is expected to launch in April 2023 will spend three years studying Jupiter and three of its icy satellites, Callisto, Europa, and Ganymede. Scientists want to find out if Ganymede’s ocean might be habitable.
Europa Clipper will launch in 2024 and perform 50 dedicated flybys around Earth after it arrives in 2030. Europa Clipper will eventually transition from an altitude of 1,700 miles (2.736 km) to 16 miles (26 km) above the moon’s surface. This could allow scientists to determine if there is an interior ocean and if it could sustain life.