The Juno ballistic capsule ’s focus has turned from Jupiter itself to its moons , and a fly - by of Io has produced worthful information for understanding the Solar System ’s most volcanic universe . Among other things , it show just how widespread Io ’s lava lake really are , and reveals that when a crust forms on them it is often border by a ring of still - liquid lava .
When Galileo discover Jupiter ’s four largest moons , he considered them so exchangeable he was at first loath to name them , give them phone number instead . TheVoyager 1spacecraft turn that on its head , revealing mankind with very different characters – most notably Io , perhaps the most classifiable world we have seen up close .
The Voyager craft blemish a volcanic clap on Io and evidence this was the average , not the elision . We now recognize Io has some expectant lava flows from these eruptions , but lava lakes within volcanic bowls know as paterae are much more vulgar .
Chors Patera, a lava lake on Io, reveals a hot ring around its edge when seen in infrared. The lake is thought to be largely covered by a thick, molten crust, with a hot ring around the edges where lava from Io’s interior is directly exposed to space.Image Credit: NASA/JPL-Caltech/SwRI/ASI/INAF/JIRAM/MSSS
Io ’s volcanism is a outcome of neighboring moons and Jupiter treating it like a strain bollock , pulling and relaxing it in elbow room that release heat deep down . Other moons are also impress , but only to the point of melting water to makeinternal oceans . The forces on Io are large enough to dissolve silicate rock , causing magma to bristle to the control surface .
Junopassed byIo at a distance of 35,000 kilometer ( 21,700 miles or a tenth the distance from Earth to the Moon ) in May 2023 . The Galileo Spacecraft got much , but Juno is equipped with better instruments , admit the Jovian Infrared Auroral Mapper ( JIRAM ) , which like the JWST operates in infrared .
Like a lot of Juno ’s equipment , JIRAM was plan for what it could tell us about Jupiter , but its capabilities turn out to be quite well suited for investigating of the moonlight .
“ The high spatial resolve of JIRAM ’s infrared image , combined with the favorable position of Juno during the flybys , revealed that the whole surface of Io is covered by lava lakes bear in caldera - like features , ” said Dr Alessandro Mura of the National Institute for Astrophysics in Rome in astatement . “ In the area of Io ’s surface in which we have the most complete data point , we guess about 3 per centum of it is cover by one of these molten lava lake . ” That ’s equivalent to if the lava - filled volcanic crater lead behind by volcanic eruption on Earth covered a combined area almost as large as Russia .
Sunlight at Io is far too weak to keep thelavaliquid for long , so a impudence quickly shape on each lake ’s surface . However , JIRAM has shown that in some cases a liquid rim live around the edge , but with no house of disgorge over . alternatively of throwing a ring into the fire , on Io , the doughnut themselves are flaming .
Mura and co - authors consider they can describe similar , although much rarer , situations on Earth .
“ We now have an idea of what is the most frequent eccentric of volcanism on Io : enormous lakes of lava where magma goes up and down , ” said Mura . “ The lava crust is forced to break against the paries of the lake , form the typical lava ring seen inHawaiian lava lake . The walls are likely C of cadence high , which explain why magma is generally not note spilling out of the paterae [ arena - shaped features create by volcanism ] and be active across the Sun Myung Moon ’s surface . ”
In this view , friction between the encrustation and the surrounding wall breaks the incrustation at the edges , allowing us to see the still - molten material to a lower place . The investigator studying Juno ’s images have an alternative explanation , although they consider it less probable . In this view , magma rise near the eye of thelakeand forms a impudence that sinks towards the outskirts , permit lava to be assure over the top .
Juno has made four subsequentIo flybys , some of them well closer , since the one the cogitation is found on , and another is coming soon . Images from these are still being investigated , and may settle the debate as to what is producing these lava rings , which could be fed into models of how magma lift on Io , helping us translate its inside .
The study is published open access inCommunications Earth and Environment .
