Space, made the most accurate map of Io, the infernal moon of Jupiter

242 hot spots indicating the presence of volcanoes have been identified thanks to the data collected by the Jiram instrument built by Asi, Leonardo and Inaf and on board the NASA Juno mission

Made the most accurate map of thethe infernal Jupiter’s moon full of volcanoes. Thanks to the data collected by Jiram tool on board the NASA Juno mission, a research team led by the Italian National Institute of Astrophysics has identified 242 ‘hot spots’, or hot areas that indicate the presence of volcanoes, of which 23 not previously observed on Jupiter’s innermost satellite. INAF and the Italian Space Agency point out that the data indicate a higher concentration of volcanic hot spots in the polar regions than in intermediate latitudes. According to the scientists, this is the “best mapping ever obtained remotely”.

The infernal moon Io – the innermost of the regular ones of the Jovian system – is the most volcanically active body in the entire solar system and a recent article published in the journal Geophysical Research Letters (Grl) thus sheds new light on the volcanic properties of this satellite natural. In particular, Asi and Inaf report that the new information comes thanks to the new data collected by Jiram-Jovian InfraRed Auroral Mapper, one of the eight instruments on board the NASA Juno probe. The discovery speaks a lot of Italian given that the instrument was funded by theAsirealized by Leonardo and with the scientific responsibility of theInaf.

Asi and Inaf explain that the article outlines “the most recent map of the distribution of hot spots – hot volcanic points – of Io produced with remote Jiram data at the best spatial scale currently available. The researchers, led by Inaf, managed to also obtain better coverage of the regions of Io close to the poles than in the past. Francesca Zambon, member of the Jiram group, researcher of the INAF of Rome and first author of the article published on GRL, explains that “the map of the hot spots presented in our work is the most up-to-date among those based on spatial remote sensing data”. The Inaf researcher argues that “by analyzing the infrared images acquired by Jiram, we have identified 242 hot volcanic points, of which 23 not present in other catalogs and located in the most cases in the polar regions, thanks to the peculiar orbit of the Juno spacecraft”.

Researcher Zambon adds that “comparison of our study with the most recent catalog reveals that Jiram observed 82% of the previously identified most powerful hot spots, and half of the intermediate potency hot spots, thus demonstrating that these are still active”. However, observes Zambon, “Jiram has only detected about half of the weakest hot spots previously reported” and for the INAF scientist “there are two explanations: either Jiram’s resolution is not sufficient to detect these weak hot spots, or the activity of these effusive centers may have faded or stopped”.

When NASA’s Voyager 1 space probe approached Io, the innermost of Jupiter’s Galilean satellites, in March 1979, images sent back to Earth revealed that its surface appeared to be dotted with a multitude of hot volcanic centers, with massive lava flows and tall plumes. up to a few hundred kilometres. Subsequently, the exploration conducted above all by the NASA Galileo mission clarified that these hot spots are very many: some hundreds, many of which with almost constant activity.

The moon Io shows many volcanic centers, triggered mainly by the powerful tidal forces exerted by Jupiter. According to the scientists, the study of the volcanic activity of this Jovian satellite is “the key to understanding the nature of its geological processes and its internal evolution. The distribution of the hot spots and their spatial and temporal variability are important for defining the characteristics of the tidal heating and the mechanisms by which heat escapes from the interior”.

Alessandro Mura, leader of the Jiram group and researcher at INAF in Rome, explains that “one of the major open points in understanding the internal structure of Io is whether the volcanic activity observable on the surface is due to a global magma ocean present in the mantle “, or to magma chambers that penetrate the crust at shallower depths. Jiram’s observations are still ongoing, and future higher-definition images will be essential to better highlight the weak hot spots and to clarify Io’s internal structure”.

Other aspects of the study are clarified by Giuseppe Sindoni, head of the Jiram project for ASI, who points out that “the surface of the Jovian moon Io is very dynamic, with volcanoes and lava emissions in continuous evolution, as demonstrated by this important result obtained by the our Jiram tool and the great work done by the team.” “The extension of the Juno mission until 2025 will allow us to monitor this evolution and to better understand the physical processes that drive such a complex body with features similar to our primordial Earth, also in anticipation of future dedicated missions” Sindoni also observes.

The Juno spacecraft was launched in August 2011 from Cape Canaveral and has been in orbit around Jupiter since July 2016. Since then it has traveled 235 million kilometers. Juno is still NASA’s most distant probe in planetary orbit, and will continue its surveys of the largest planet in the Solar System until September 2025. At the end of the year, on December 30, 2023, during the 57th orbit around Jupiter, the Juno probe will make its closest ever pass to Io, at a minimum distance of about 4800 kilometers. NASA’s Europa Clipper and ESA’s Juice missions, which will operate in the Jupiter system in the 2030s, will never get close to such distances. It will therefore be crucial that Juno can also conduct observations with Jiram during all the upcoming opportunities foreseen in 2023.