NASA is ending 2023 with a splash as its Juno spacecraft on Saturday will make the closest approach to Jupiter's moon, Io, considered by the space agency as the most volcanic world in our solar system.
The orbiter, which has monitored Io from afar since arriving at Jupiter in 2016, will get as close as 930 miles from the moon's surface. The space agency said Io's volcanoes are at times so powerful, they can be seen with large telescopes on Earth, and Io even has lakes of molten silicate lava on its surface.
"By combining data from this flyby with our previous observations, the Juno science team is studying how Io's volcanoes vary," Scott Bolton, Juno's principal investigator at the Southwest Research Institute in San Antonio, said in a news release. "We are looking for how often they erupt, how bright and hot they are, how the shape of the lava flow changes, and how Io's activity is connected to the flow of charged particles in Jupiter's magnetosphere."
Juno entered Jupiter's orbit on July 4, 2016, and is the first spacecraft to peer below the planet's dense clouds to answer questions about the gas giant, the largest planet in our solar system. NASA said the orbiter has performed 56 flybys of Jupiter — Saturday will mark its 57th — as well as the largest of its 95 moons, Ganymede, and Europa, its fourth-largest moon. Io is the planet's third-largest moon and Juno has not approached Jupiter's second-largest moon, Callisto, which has an orbit further away from the planet than the other three moons.
NASA said Juno is also set to get as close as 930 miles to Io's surface on Feb. 3, 2024. The spacecraft has been monitoring Io's volcanic activity from about 6,830 miles to 62,100 miles and has provided the first views of the moon's north and south poles.
"With our pair of close flybys in December and February, Juno will investigate the source of Io's massive volcanic activity, whether a magma ocean exists underneath its crust, and the importance of tidal forces from Jupiter, which are relentlessly squeezing this tortured moon," Bolton said.
NASA said Juno's Jovian Infrared Auroral Mapper will collect heat signatures emitted by volcanoes and volcanic craters covering the moon's surface. The orbiter's Stellar Reference Unit will obtain the highest-resolution image of the surface to date, and the JunoCam imager will take visible-light color images.
During its flybys of Jupiter, the spacecraft endured one of the solar system's most punishing radiation environments. Jupiter's magnetic field is 16 to 54 times as powerful as Earth's. Near the planet, NASA said, the magnetic field traps swarms of charged particles and accelerates them to create intense radiation that bombards the innermost moons and can damage spacecraft.
"The cumulative effects of all that radiation has begun to show on JunoCam over the last few orbits," Ed Hirst, Juno's project manager at NASA's Jet Propulsion Laboratory in Southern California, said in the news release. "Pictures from the last flyby show a reduction in the imager's dynamic range and the appearance of 'striping' noise. Our engineering team has been working on solutions to alleviate the radiation damage and to keep the imager going."
Juno's extended mission is scheduled to end in September 2025, and it likely will be intentionally crashed into Jupiter's atmosphere.
Michael Katz ✉
Michael Katz is a Newsmax reporter with more than 30 years of experience reporting and editing on news, culture, and politics.
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