Juno may have found new volcano on Jupiter’s moon Io
A new heat source detected near the south pole of Jupiter’s moon Io may be the site of a previously undiscovered volcano, according to researchers working with data returned by NASA’s Juno spacecraft.
Images captured by Juno’s Jovian InfraRed Auroral Mapper (JIRAM) instrument in the infrared reveal a hot spot detected Dec. 16, 2017, when the probe came within 290,000 miles (470,000 kilometers) of the innermost Galilean moon. In infrared images, brighter colors indicate higher temperatures.
Io is the smallest of Jupiter’s four Galilean moons, which were discovered by Galileo Galilei in 1610. It has a diameter of 2,264 miles (3,640 kilometers) and is the Solar Systems’ most volcanically active world. There are 150 known active volcanoes that spew lava up to 250 miles (400 kilometers) high into space.
The moon’s volcanoes were discovered during previous missions to Jupiter including Voyagers 1 and 2, Galileo, Cassini, and New Horizons. Scientists suspect Io has approximately 250 more still-undiscovered volcanoes.
Churning activity within the moon’s interior is driven by the powerful gravitational pull of Jupiter and by the gravitational influences of the gas giant’s other three Galilean moons: Europa, Ganymede and Callisto.
“The new Io hot spot JIRAM picked up is about 200 miles (300 km) from the nearest previously mapped hot spot,” said Juno co-investigator Alessandro Mura of the National Institute for Astrophysics (INAF) in Rome in a news release on the Juno mission website. “We are not ruling out movement or modification of a previously discovered hot spot, but it is difficult to imagine one could travel such a distance and still be considered the same feature.”
Juno has traveled almost 146 million miles (235 million kilometers) since entering orbit around Jupiter on July 4, 2016.
Circling Jupiter in an elliptical orbit, it has a science mission that takes it close to the planet every 53 days. During these close flybys, the probe studies the giant planet’s cloud tops and peers beneath them to image its auroras in an effort to learn more about Jupiter’s origins, structure, mangetosphere, and atmosphere, according to NASA.
Since orbit insertion, Juno has flown as close as 2,100 miles (3,400 kilometers ) above the giant planet’s cloud tops. The spacecraft’s 13th close flyby occurred on July 16, 2018. Future flybys are expected to come even closer to both the cloud tops and to Io.
Juno scientists are currently analyzing JIRAM data collected last December and will integrate it with information that will be gathered in upcoming flybys through the mission’s end in July 2021.
Laurel Kornfeld is an amateur astronomer and freelance writer from Highland Park, NJ, who enjoys writing about astronomy and planetary science. She studied journalism at Douglass College, Rutgers University, and earned a Graduate Certificate of Science from Swinburne University’s Astronomy Online program. Her writings have been published online in The Atlantic, Astronomy magazine’s guest blog section, the UK Space Conference, the 2009 IAU General Assembly newspaper, The Space Reporter, and newsletters of various astronomy clubs. She is a member of the Cranford, NJ-based Amateur Astronomers, Inc. Especially interested in the outer solar system, Laurel gave a brief presentation at the 2008 Great Planet Debate held at the Johns Hopkins University Applied Physics Lab in Laurel, MD.