Ready for My Close-Up: NASA’s Juno Probe to Fly Just 932 Miles Over Jupiter’s Volcanic Moon Io

Since arriving in Jovian orbit in 2016, NASA’s Juno space probe has investigated the massive planet as well as several of its most prominent moons. Once its mission is completed, the probe will plunge into the gas giant’s atmosphere on one final deadly mission.

Juno is going to Io, NASA said on Wednesday.

The space agency’s Joint Propulsion Laboratory (JPL) said in a news release that Juno would photograph Io (pronounced “eye-oh”) as it zips past on Thursday, part of a new effort to study the mysterious volcanic moon.

“The team is really excited to have Juno’s extended mission include the study of Jupiter’s moons. With each close flyby, we have been able to obtain a wealth of new information,” Juno Principal Investigator Scott Bolton, of the Southwest Research Institute in San Antonio, said in the release. “Juno sensors are designed to study Jupiter, but we’ve been thrilled at how well they can perform double duty by observing Jupiter’s moons.”

In July, Juno passed about 50,000 miles from Io, but as it focuses more on the tortured world over the next year, Juno will eventually make its closest pass at just 932 miles above its surface.

NASA Juno Images From Jovian Moon Revealed

© NASA

Jupiter’s third-largest moon, Io is bigger than Earth’s moon and the most dense of any moon in the solar system. Its surface is dotted with dozens of volcanoes belching sulfur and sulfur dioxide, which have painted the surface yellow and are driven by the constant pulling on its interior by Jupiter and several of its other large moons. Much of this information was gathered from prior probes, including the Voyager and Galileo missions, in the 1970s and 1980s.

Juno has previously made close passes over Callisto, Ganymede and Europa, three other Jovian moons.

Along with Io, the four are known as the Galilean Moons, because they were the first to be observed by Italian astronomer Galileo Galilei in 1610. Indeed, they were the first moons observed around any planet other than Earth, helping to trigger contentious debates about the structure of the solar system.

In the present day, Jupiter is known to have at least 80 natural satellites, of which the Galilean Moons are by far the most massive.

Juno’s mission is set to last until 2025, when it will begin its final task: a one-way plunge into the heart of the gas giant.