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A NASA spacecraft prepares for the first in a series of close encounters with the most volcanic place in the solar system. The Juno spacecraft will fly by Jupiter’s moon Io on Thursday, December 15th.
The maneuver will be one of them nine flybys of Io made by Juno over the next year and a half. Two of the encounters take place at a distance of just 1,500 kilometers from the lunar surface.
Juno captured a glowing infrared view of Io on July 5 from a distance of 50,000 miles (80,000 kilometers). The brightest points in this image correspond to the hottest temperatures on Io, which is home to hundreds of volcanoes – some of which can eject lava fountains tens of kilometers high.
Scientists will use Juno’s observations of Io to learn more about this network of volcanoes and how its eruptions interact with Jupiter. The moon is constantly being pulled by Jupiter’s massive gravitational pull.
“The team is very pleased that Juno’s expanded mission includes the study of Jupiter’s moons. Each close flyby allowed us to glean a wealth of new information,” Scott Bolton, Juno principal investigator at the Southwest Research Institute in San Antonio, said in a statement.
“Juno sensors were designed to study Jupiter, but we were amazed at how well they could do double duty by observing Jupiter’s moons.”
The spacecraft recently acquired a new image of Jupiter’s northernmost cyclone on September 29th. Jupiter’s atmosphere is dominated by hundreds of cyclones and many clusters at the planet’s poles.
The Juno spacecraft has been orbiting Jupiter since 2016 to uncover more details about the giant planet, focusing on flybys of Jupiter’s moons during the extended portion of its mission, which began last year and is expected to last through late 2025.
Juno flew past Jupiter’s moon Ganymede in 2021, followed by Europa earlier this year. The spacecraft used its instruments to peer beneath the icy crust of both moons, collecting data on the interior of Europa, where a salty ocean is thought to exist.
The ice sheet that makes up Europa’s surface is between 10 and 15 miles (16 and 24 kilometers) thick, and the ocean it likely sits on is estimated to be 40 to 100 miles (64 to 161 kilometers) deep.
The data and images captured by Juno could help inform two separate missions headed to Jupiter’s moons over the next two years: JUpiter ICy Moons Explorer and the European Space Agency NASA’s Europa Clipper mission.
The first, expected to launch in April 2023, will spend three years studying Jupiter and three of its icy moons — Ganymede, Callisto and Europa — in depth. All three moons are thought to have oceans beneath their ice-covered crusts, and scientists want to investigate whether Ganymede’s ocean might be habitable.
Europa Clipper will be launched in 2024 to perform a special series of 50 flybys around the moon after its arrival in 2030. Europa Clipper may eventually go from an altitude of 1,700 miles (2,736 kilometers) to just 16 miles (26 kilometers) above the lunar surface, able to help scientists determine if there really is an ocean inside and if the moon is alive could support.