In February 2001 an eruption from the Surt volcano on the Jupiter-facing hemisphere of Io, the volcanic epi-center of our solar system, occurred with an estimated output of 78,000 Gigawatts. By comparison, the 1992 eruption of Mt Etna, Sicily, was estimated at 12 Gigawatts. During its peak, observed by the WM Keck II Telescope on Hawaii, its output almost matched the eruptive power of all of Io’s active volcanoes combined.
Fast forward to December 2017, data collected by NASA’s Juno spacecraft using its Jovian InfraRed Auroral Mapper (JIRAM) instrument point to a new heat source close to the south pole of Io that could indicate a previously undiscovered volcano on the small moon of Jupiter. The infrared data was collected when Juno was about 290,000 miles (470,000 kilometers) away from the moon.
“The new Io hotspot JIRAM picked up is about 200 miles (300 kilometers) from the nearest previously mapped hotspot,” said Alessandro Mura, a Juno co-investigator from the National Institute for Astrophysics in Rome. “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.”
The image above highlights the location of the new heat source close to the south pole of Io. The image was generated from data collected on Dec. 16, 2017, by the Jovian Infrared Auroral Mapper (JIRAM) instrument aboard NASA’s Juno mission when the spacecraft was about 290,000 miles (470,000 kilometers) from the Jovian moon. The scale to the right of image depicts of the range of temperatures displayed in the infrared image. Higher recorded temperatures are characterized in brighter colors – lower temperatures in darker colors.
This infrared image of the southern hemisphere of Jupiter’s moon Io was derived from data collected by the Jovian Infrared Auroral Mapper (JIRAM) instrument aboard NASA’s Juno spacecraft on Dec. 16, 2017, when the spacecraft was about 290,000 miles (470,000 kilometers) from the Jovian moon.
This annotated image highlights the location of the new heat source in the southern hemisphere of the Jupiter moon Io. The image was generated from data collected on Dec. 16, 2017, by the Jovian Infrared Auroral Mapper (JIRAM) instrument aboard NASA’s Juno mission when the spacecraft was about 290,000 miles (470,000 kilometers) from the Jovian moon.
The Juno team will continue to evaluate data collected on the Dec. 16 flyby, as well as JIRAM data that will be collected during future (and even closer) flybys of Io. Past NASA missions of exploration that have visited the Jovian system (Voyagers 1 and 2, Galileo, Cassini and New Horizons), along with ground-based observations, have located over 150 active volcanoes on Io so far. Scientists estimate that about another 250 or so are waiting to be discovered.
Juno has logged nearly 146 million miles (235 million kilometers) since entering Jupiter’s orbit on July 4, 2016. Juno’s 13th science pass will be on July 16.
Juno launched on Aug. 5, 2011, from Cape Canaveral, Florida. During its mission of exploration, Juno soars low over the planet’s cloud tops — as close as about 2,100 miles (3,400 kilometers). During these flybys, Juno is probing beneath the obscuring cloud cover of Jupiter and studying its auroras to learn more about the planet’s origins, structure, atmosphere and magnetosphere.
The Daily Galaxy via NASA/JUNO
Image credit: Credits: NASA/JPL-Caltech/SwRI/ASI/INAF/JIRAM