Latest news with #ScottBolton
WIRED
15-06-2025
- Science
- WIRED
The Mysterious Inner Workings of Io, Jupiter's Volcanic Moon
Jun 15, 2025 7:00 AM Recent flybys of the fiery world refute a leading theory of its inner structure—and reveal how little is understood about geologically active moons. Photograph: NASA/JPL-Caltech/SwRI/ASI/INAF/JIRAM The original version of this story appeared in Quanta Magazine. Scott Bolton's first encounter with Io took place in the summer of 1980, right after he graduated from college and started a job at NASA. The Voyager 1 spacecraft had flown past this moon of Jupiter, catching the first glimpse of active volcanism on a world other than Earth. Umbrella-shaped outbursts of magmatic matter rocketed into space from all over Io's surface. 'They looked amazingly beautiful,' said Bolton, who is now based at the Southwest Research Institute in Texas. 'It was like an artist drew it. I was amazed at how exotic it looked compared to our moon.' Scientists like Bolton have been trying to understand Io's exuberant volcanism ever since. A leading theory has been that just below the moon's crust hides a global magma ocean, a vast contiguous cache of liquid rock. This theory dovetails neatly with several observations, including ones showing a roughly uniform distribution of Io's volcanoes, which seem to be tapping the same omnipresent, hellish source of melt. But now, it appears that Io's hell has vanished—or rather, it was never there to begin with. During recent flybys of the volcanic moon by NASA's Juno spacecraft, scientists measured Io's gravitational effect on Juno, using the spacecraft's tiniest wobbles to determine the moon's mass distribution and therefore its internal structure. The scientists reported in Nature that nothing significant is sloshing about just beneath Io's crust. 'There is no shallow ocean,' said Bolton, who leads the Juno mission. Independent scientists can find no fault with the study. 'The results and the work are totally solid and pretty convincing,' said Katherine de Kleer, a planetary scientist at the California Institute of Technology. The data has reopened a mystery that spills over into other rocky worlds. Io's volcanism is powered by a gravity-driven mechanism called tidal heating, which melts the rock into magma that erupts from the surface. Whereas Io is the poster child for this mechanism, tidal heating also heats many other worlds, including Io's neighbor, the icy moon Europa, where the heat is thought to sustain a subterranean saltwater ocean. NASA launched the $5 billion Clipper spacecraft to search Europa's sky for signs of life in the proposed underground ocean. A map of Io's surface, created with images from the Voyager 1 and Galileo missions, shows the wide distribution of the moon's volcanoes. The large red ring is sulfurous fallout from the plume of the Pele volcano. Photograph: US Geological Survey But if Io doesn't have a magma ocean, what might that mean for Europa? And, scientists now wonder, how does tidal heating even work? Melting Magma Heat drives geology, the rocky foundation upon which everything else, from volcanic activity and atmospheric chemistry to biology, is built. Heat often comes from a planet's formation and the decay of its radioactive elements. But smaller celestial objects like moons have only tiny reserves of such elements and of residual heat, and when those reserves run dry, their geological activity flatlines. Or, at least, it should—but something appears to grant geologic life to small orbs throughout the solar system long after they should have geologically perished. Io is the most flamboyant member of this puzzling club—a burnt-orange, crimson, and tawny Jackson Pollock painting. The discovery of its over-spilling cauldrons of lava is one of the most famous tales in planetary science, as they were predicted to exist before they were discovered. NASA's Voyager 1 probe photographed Io in 1979, revealing the first glimpse of volcanism beyond Earth. In this photo mosaic, a lava plume is seen emanating from Loki Patera, now known to be the moon's largest volcano. Photograph: NASA/JPL/USGS On March 2, 1979, a paper in Science ruminated on Io's strange orbit. Because of the positions and orbits of neighboring moons, Io's orbit is elliptical rather than circular. And when Io is closer to Jupiter, it experiences a stronger gravitational pull from the gas giant than when it is farther away. The study authors figured that Jupiter's gravity must therefore be constantly kneading Io, pulling its surface up and down by up to 100 meters, and, per their calculations, generating a lot of frictional heat within it—a mechanism they described as 'tidal heating.' They conjectured that Io may be the most intensely heated rocky body in the solar system. 'One might speculate that widespread and recurrent surface volcanism would occur,' they wrote. Just three days later, Voyager 1 flew by. An image taken on March 8 documented two gigantic plumes arching above its surface. After ruling out all other causes, NASA scientists concluded that Voyager had seen an alien world's volcanic eruptions. They reported their discovery in Science that June, just three months after the prediction. The planetary science community quickly coalesced around the idea that tidal heating within Io is responsible for the never-ending volcanism on the surface. 'The unknown part that's been an open question of decades is what that means for the interior structure,' said Mike Sori, a planetary geophysicist at Purdue University. Where is that tidal heating focused within Io, and just how much heat and melting is it generating? Courtest of Mark Belan/Quanta Magazine NASA's Galileo spacecraft studied Jupiter and several of its moons around the turn of the millennium. One of its instruments was a magnetometer, and it picked up a peculiar magnetic field emanating from Io. The signal appeared to be coming from an electrically conductive fluid—a lot of fluid, in fact. After years of study, scientists concluded in 2011 that Galileo had detected a global magma ocean just below Io's crust. Whereas Earth's mantle is mostly solid and plasticky, Io's subsurface was thought to be filled with an ocean of liquid rock 50 kilometers thick, or almost five times thicker than the Pacific Ocean at its deepest point. A similar magnetic field was coming from Europa, too—in this case, apparently generated by a vast ocean of salty water. The implications were profound: With a lot of rocky material, tidal heating can make oceans of magma. With plenty of ice, it can create oceans of potentially habitable liquid water. Volcanic Vanishing Act By the time the Juno spacecraft started swinging around Jupiter in 2016, the belief that Io had a magma ocean was widespread. But Bolton and his colleagues wanted to double-check. A sequence of images taken over the course of eight minutes by NASA's New Horizons probe in 2007 shows an eruption by the Tvashtar Paterae volcanic region. The plume in this false-color image rises 330 kilometers from the moon's surface. Video: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute During flybys in December 2023 and February 2024, Juno came within 1,500 kilometers of Io's scorched surface. Although the remarkable images of active volcanoes drew everyone's attention, the goal of these flybys was to find out if a magma ocean truly lay beneath the moon's rocky skin. To investigate, the team used an unlikely tool: Juno's radio transponder, which communicates with Earth, sending and receiving signals. Because of Io's unevenly distributed mass, its gravitational field isn't perfectly symmetrical. That uneven gravitational field subtly alters the motion of Juno as it flies by, causing it to accelerate or decelerate a little. That means Juno's radio transmissions will experience the Doppler effect, where the wavelength shifts slightly in response to Io's uneven gravitational field. By looking at the incredibly small shifts in the transmissions, Bolton's team was able to create a high-fidelity picture of Io's gravitational field and use that to determine its internal structure. 'If there were indeed a global magma ocean, you'd see a lot more distortion as Io orbited around Jupiter and as the tidal forces flexed it and changed its shape,' said Ashley Davies, a volcanologist at NASA's Jet Propulsion Laboratory who wasn't involved with the new study. But Bolton's team did not find this level of distortion. Their conclusion was clear. 'There cannot be a shallow magma ocean fueling the volcanoes,' said study coauthor Ryan Park, a Juno co-investigator at the Jet Propulsion Laboratory. The Cassini-Huygens mission photographed Io against the backdrop of Jupiter in 2001. Photograph: NASA/JPL/University of Arizona So what else might be powering Io's volcanoes? On Earth, discrete reservoirs of magma of different types—from the tarlike viscous matter that powers explosive eruptions to the runnier, honey-esque stuff that gushes out of some volcanoes—are located within the crust at various depths, all created by the interactions of tectonic plates, the moving jigsaw pieces that make up Earth's surface. Io lacks plate tectonics and (perhaps) a diversity of magma types, but its crust may nevertheless be peppered with magma reservoirs. This was one of the original lines of thought until Galileo's data convinced many of the magma ocean theory. The new study doesn't rule out a far deeper magma ocean. But that abyssal cache would have to be filled with magma so iron-rich and dense (because of its great depth) that it would struggle to migrate to the surface and power Io's volcanism. 'And at some depth, it becomes tricky to distinguish between what we would call a deep magma ocean versus a liquid core,' Park said. For some, this raises an irreconcilable problem. Galileo's magnetometer detected signs of a shallow magma ocean, but Juno gravity data has emphatically ruled that out. 'People are not really disputing the magnetometer results, so you have to make that fit with everything else,' said Jani Radebaugh, a planetary geologist at Brigham Young University. Researchers disagree on the best interpretation of the Galileo data. The magnetic signals 'were taken as probably the best evidence for a magma ocean, but really they weren't that strong,' said Francis Nimmo, a planetary scientist at the University of California, Santa Cruz, and a coauthor of the new study. The induction data couldn't distinguish between a partly molten (but still solid) interior and a fully molten magma ocean, he said. Heavy Water Perhaps the main reason scientists study Io is because it teaches us about the fundamentals of tidal heating. Io's tidal heating engine remains impressive—there's clearly a lot of volcano-feeding magma being generated. But if it's not producing a subsurface magma ocean, does that mean tidal heating doesn't generate water oceans, either? Scientists remain confident that it does. Nobody doubts that Saturn's moon Enceladus, which is also tidally heated, contains an underground saltwater ocean; the Cassini spacecraft not only detected signs of its existence but directly sampled some of it erupting out of the moon's South Pole. And although there is some light skepticism about whether Europa has an ocean, most scientists think it does. The smooth, lightly scratched surface of Jupiter's icy moon Europa, photographed by the Juno spacecraft in 2022, shows no sign of what lies beneath: in all likelihood, a vast saltwater ocean. Photograph: NASA/JPL-Caltech/SwRI/MSSS Crucially, unlike Io's odd magnetic field, which seemed to indicate that it concealed an ocean's worth of fluid, Europa's own Galileo-era magnetic signal remains robust. 'It's a pretty clean result at Europa,' said Robert Pappalardo, the Europa mission's project scientist at the Jet Propulsion Laboratory. The icy moon is far enough from Jupiter and the intense plasma-flooded space environment of Io that Europa's own magnetic induction signal 'really sticks out.' But if both moons are tidally heated, why does only Europa have an inner ocean? According to Nimmo, 'there's a fundamental difference between a liquid-water ocean and a magma ocean. The magma wants to escape; the water really doesn't.' Liquid rock is less dense than solid rock, so it wants to rise and erupt quickly; the new study suggests that it doesn't linger at depth long enough inside Io to form a massive, interconnected ocean. But liquid water is, unusually, denser than its solid icy form. 'Liquid water is heavy, so it collects into an ocean,' Sori said. 'I think that's the big-picture message from this paper,' Sori added. Tidal heating might struggle to create magma oceans. But on icy moons, it can easily make watery oceans due to the bizarrely low density of ice. And that suggests life has a multitude of potentially habitable environments throughout the solar system to call home. Hell's Poster Child The revelation that Io is missing its shallow magma ocean underscores just how little is known about tidal heating. 'We've never really understood where in Io's interior the mantle is melting, how that mantle melt is getting to the surface,' de Kleer said. Our own moon shows evidence of primeval tidal heating too. Its oldest crystals formed 4.51 billion years ago from the stream of molten matter that got blasted off Earth by a giant impact event. But a lot of lunar crystals seem to have formed from a second reservoir of molten rock 4.35 billion years ago. Where did that later magma come from? Nimmo and coauthors offered one idea in a paper published in Nature in December: Maybe Earth's moon was like Io. The moon was significantly closer to Earth back then, and the gravitational fields from the Earth and the sun were battling for control. At a certain threshold, when the gravitational influence of both were roughly equal, the moon might have temporarily adopted an elliptical orbit and gotten tidally heated by Earth's gravitational kneading. Its interior might have remelted, causing a surprise secondary flourish of volcanism. But exactly where within the moon's interior its tidal heating was concentrated—and thus, where all that melting was happening—isn't clear. Perhaps if Io can be understood, so too can our moon—as well as several of the other satellites in our solar system with hidden tidal engines. For now, this volcanic orb remains maddeningly inscrutable. 'Io's a complicated beast,' Davies said. 'The more we observe it, the more sophisticated the data and the analyses, the more puzzling it becomes.' Original story reprinted with permission from Quanta Magazine, an editorially independent publication of the Simons Foundation whose mission is to enhance public understanding of science by covering research developments and trends in mathematics and the physical and life sciences.
Forbes
07-05-2025
- Science
- Forbes
NASA's Spacecraft Reveals Io To Be A Hellishly Active Volcanic Moon
Io, one of the four Galilean moons of Jupiter, as seen by the Galileo probe, circa 1997. (Photo by ... More Space Frontiers/) Getty Images New data from NASA's Juno $1.2 billion spacecraft now in orbit around Jupiter reveals that the massive planet's Galilean moon of Io has recently undergone the most massive eruptions ever observed in our solar system. Only about the size of our own moon, Io is much hotter and more volcanically active than the Juno team could have ever imagined. There's nothing in our solar system that we've seen that has so many volcanoes all going off at the same time, continuously, hundreds of them, Scott Bolton, principal investigator of NASA's Juno at the Southwest Research Institute in San Antonio, tells me at the European Geosciences Union General Assembly in Vienna. Io has volcanoes all over the place, he says. Juno was able to accomplish a couple of totally new things. Because we were in a polar orbit, we saw the poles of Io for the first time and there were volcanoes all over both poles, says Bolton. There were multiple eruptions around the same area over the South Pole which suggested that maybe there was one reservoir that somehow got active, and a few eruptions all happened at the same time, he says. Io is in orbit around Jupiter, but it's far from a perfectly circular orbit. On one side of the orbit, it's a little bit closer to Jupiter than on the other side, says Bolton. Jupiter is pulling on the side that's closest to it a little bit more than the side that's far away from it and distorts its spherical shape, he says. So, Io itself is constantly being gravitationally squeezed by Jupiter, causing Io's insides to become very hot and molten and eventually erupt, says Bolton. Why is studying such a volcanic, eruptive moon like Io important? Here's this moon that's constantly spewing out volcanoes, says Bolton. By studying Io, he says, we can learn about the volcanoes here on the earth, what's similar, what's different, what are the conditions that cause these things? On 30 December 2023, the Juno spacecraft, exploring the Jovian system, approached the volcanic moon ... More Io at a distance of just 1500 km (930 miles). A similar encounter is scheduled to take place on 3 February 2024. The probe is monitoring the moon's volcanic activity getty No spacecraft has ever gone into this hazardous, high-radiation environment; the real danger is near Jupiter where we're in this elliptical, polar orbit, says Bolton. But Juno got within 1500 km above Io's surface, he says. One reason the mission is a challenge is the nature of the planet Jupiter itself. Jupiter is more massive than all the other planets in our solar system put together, says Bolton. It's got the strongest magnetic field, largest gravity field and the most ferocious aurorae, including the harshest radiation belts in the entire solar system, he says. Then sitting in the same system is another extreme object, Io, which is the most volcanic body in the solar system, says Bolton. Lava Lakes We're possibly seeing lakes of lava, possibly that are kind of crusted over, like you see in Hawaii when lava flows get crusted over and look dark, says Bolton. People walk on them, even though it's quite dangerous, because underneath is unbelievably hot lava, he says. Juno's data suggests that about 10 percent of Io's surface has these remnants of slowly cooling lava just below the surface, says NASA. As for the overall mission's success? Even though the mission had some minor hiccups, it's been a grand success. Once we got there, we saw some symptoms with the rocket motor and its fuel that made us a little nervous about whether we should fire that or not, says Bolton. We were in an orbit that would work; it was just a longer orbit and so we decided not to fire the engine and just stay in that 53-day orbit, he says. One of Juno's ten active instruments, the Microwave Radiometer (MWR) was specifically invented for the mission. We're looking at maybe flying one of these instruments right here on Earth to study our own volcanoes, says Bolton. This microwave radiometer was invented for the Juno mission to look below the cloud tops of Jupiter and understand its composition, the dynamics of its storms, he says. But when we pointed at Io, somewhat serendipitously, it allowed us to see into the rock and lava to provide the first real look inside of the moon's subsurface structure, says Bolton. A further extension notwithstanding, this coming September Juno will end its current extended mission. Launched in 2011, the spacecraft arrived at Jupiter in 2016 and has been scientifically prolific ever since. The mission represents the best of NASA ingenuity. One of the greatest things that we've been able to do as humans is figure out how to navigate around the planets and stars, says Bolton. I'm totally amazed that we're able to robotically visit Jupiter, Saturn, Uranus, Neptune, and once there, go into orbit and navigate around their moons, just like driving down to the gas station, he says. In one sense, we're navigating by the stars in the same way we used to do with ancient ships, but now we're navigating between bodies of the solar system, says Bolton. Forbes How Jupiter Helped Spawn Life On Earth By Bruce Dorminey
Saba Yemen
05-05-2025
- Science
- Saba Yemen
NASA's Juno Probe reveals new secrets about Jupiter & its Volcanic Moon Io
Washington - Saba: NASA's Juno spacecraft has uncovered fascinating new details about Jupiter and its volcanic moon Io. By peering beneath Jupiter's dense cloud cover and below Io's surface, scientists have developed a more detailed model of the fast-moving jet stream around Jupiter's north pole. Simultaneously, they achieved a groundbreaking milestone by mapping subsurface temperatures on Io, revealing crucial insights into its internal structure and ongoing volcanic activity. At Jupiter's north pole, Juno found massive storms—some as large as Australia—raging amid winds reaching 160 km/h. These discoveries came after analyzing years of data, which also revealed long-term movements of a giant polar cyclone surrounded by eight other cyclones. On Io, the most volcanically active moon in the solar system, Juno detected lava flows still retaining heat just beneath the surface crust. These findings, presented on April 29 at the European Geosciences Union General Assembly in Vienna, will help scientists better understand heat transfer mechanisms in planets and moons, influencing weather, volcanic activity, and surface evolution. Scott Bolton, Juno's principal investigator, stated: "As Juno's orbit shifts into new regions of Jupiter's complex system, we're getting a closer look at the immense energy of this gas giant." The team also observed a volcanic eruption on Io during a December 2024 flyby—the most active in the moon's history—which continued spewing lava and ash until at least March 2. Surprisingly, while Io's outer crust is cooled, data shows that 10% of its subsurface contains molten lava, explaining its constant surface renewal. Shannon Brown, a Juno team scientist, explained: "Io's volcanoes, lava fields, and underground flows act like a car's radiator, efficiently transferring heat from the interior to the surface, cooling itself in the vacuum of space." During a recent flyby, Juno used radio occultation to send signals through Jupiter's thick atmosphere, revealing that the north pole's air is about 11°C cooler than surrounding areas. Unlike Earth's hurricanes, Jupiter's polar storms remain in a chaotic yet organized pattern, with cyclones slowly orbiting a central storm. Studying Jupiter's weather, internal dynamics, and moons can enhance our understanding of Earth. Computer models simulating planetary weather systems rely on universal physics, and Juno's observations help refine these models. Juno will make another close flyby of Io on May 6, passing within 88,500 km to determine if the massive eruption is still active. Whatsapp Telegram Email Print more of (International)
United News of India
01-05-2025
- Science
- United News of India
NASA Juno mission reveals volcanic action on Jupiter's moon Io
Los Angeles, May 1 (UNI) New data from NASA's Juno mission has shed light on the dynamic atmosphere of Jupiter and the volcanic activity on its fiery moon Io, according to the agency. The Juno spacecraft has gathered new findings by probing beneath Jupiter's cloud-shrouded atmosphere and studying Io's surface. The data has led to the development of a new model to better understand the fast-moving jet streams that encircle Jupiter's cyclone-covered north pole. In addition, for the first time, scientists have mapped Io's subsurface temperature profile, providing critical information about the moon's internal structure and volcanic behavior, according to findings released by mission team on Tuesday. "As Juno's orbit takes us to new regions of Jupiter's complex system, we're getting a closer look at the immensity of energy this gas giant wields," said Scott Bolton, principal investigator of the Juno mission. Juno was launched Aug. 5, 2011, and arrived at Jupiter on July 4, 2016, after a five-year, 1,740-million-mile journey. The mission is designed to explore the origin and evolution of Jupiter, the solar system, and giant planets across the cosmos. UNI XINHUA GNK
India Today
30-04-2025
- Science
- India Today
Nasa's Juno flies past Io, captures the moon glowing from volcanic explosions
Nasa Juno spacecraft, which is orbiting around Jupiter, recently flew past its moon Io and what it saw was something out of a sci-fi film. The spacecraft captured Io glowing from volcanic explosions that have battered its from Jovian orbiter reveals volcanic action on Jupiter's moon Io as seen in infrared and also sheds light on the fierce winds and cyclones of Jupiter's only has the data helped develop a new model to better understand the fast-moving jet stream that encircles Jupiter's cyclone-festooned north pole, it's also revealed for the first time the subsurface temperature profile of Io, providing insights into the moon's inner structure and volcanic #JunoMission gets under Io's skin: New data from our Jovian orbiter reveals volcanic action on Jupiter's moon Io (seen here in infrared) and also sheds light on the fierce winds and cyclones of Jupiter's atmosphere. NASA Solar System (@NASASolarSystem) April 29, 2025 'Everything about Jupiter is extreme. The planet is home to gigantic polar cyclones bigger than Australia, fierce jet streams, the most volcanic body in our solar system, the most powerful aurora, and the harshest radiation belts. As Juno's orbit takes us to new regions of Jupiter's complex system, we're getting a closer look at the immensity of energy this gas giant wields,' Scott Bolton, principal investigator of Juno combined the data from Juno's Microwave Radiometer (MWR) and Jovian Infrared Auroral Mapper (JIRAM) to make the data suggests that about 10% of the moon's surface has these remnants of slowly cooling lava just below the result may help provide insight into how the moon renews its surface so quickly as well as how heat moves from its deep interior to the team also determined that the most energetic eruption in Io's history (first identified by the infrared imager during Juno's Dec. 27, 2024, Io flyby) was still spewing lava and ash as recently as March 2. team's recent findings also focus on the cyclones that haunt Jupiter's north. Years of data from the JunoCam visible light imager and JIRAM have allowed Juno scientists to observe the long-term movement of Jupiter's massive northern polar cyclone and the eight cyclones that encircle it.
