NASA’s Juno spacecraft just made the closest flybys of Jupiter’s moon Io that any spacecraft has carried out in more than 20 years. An instrument on this spacecraft called “JunoCam” returned spectacular, high-resolution images—and raw data are now available for you to process, enhance, and investigate.
7.02.2024
NASA'S JUNO MISSION MAKES CLOSEST FLYBY PAST IO
Juno has revealed Jupiter’s volcanic moon Io as never before.
The sensitive cameras of Juno capture Io's nightside, illuminated by sunlight reflected off Jupiter's cloud tops. Several surface changes are visible include a reshaping of the compound flow field at Kanehekili (center bottom).
NASA / SwRI / JPL / MSSS / Jason Perry © CC NC SA
NASA’s Juno mission has made its closest approach yet to Io, Jupiter’s innermost Galilean moon, passing within 1,500 kilometers (930 miles) of the surface on February 3rd. These were the closest Io passes that Juno will make (though the record still goes to the Galileo mission, which passed 112 miles (181 kilometers) from Io in 2001). We now have some new stunning views of the tormented surface, many of which can be viewed on the JunoCam Gallery.
The latest close pass came just before perijove 58, meaning it's the 58th time the probe has circled the giant planet. It has been just over a month since Juno's last close pass of the moon, on December 30, 2023. NASA has revamped Juno's extended mission plan to schedule seven more flybys of Io, for 18 in all, although the remaining passes will be progressively farther away.
The recent set of flybys probed the moon's interior as well as its surface. "With our pair of close flybys in December and February, Juno will investigate the source of Io's massive volcanic activity, whether a magma ocean exists underneath its crust, and the importance of tidal forces from Jupiter, which are relentlessly squeezing this tortured moon," says Scott Bolton (Southwest Research Institute) in a recent press release.
As other missions have done before it, Juno spied active volcanoes spewing out material along the moon's limb:
NASA / JPL-Caltech / SwRI / MSSS processing: Andrea Luck CC BY 3.0
And to think, early mission proposals originally didn't even call for the mission to have a camera! Besides proving handy for publish outreach, the probe's JunoCam has also provided great closeup views of the major Jovian moons during the extended phase of the mission. Lots of these images are worked though by online volunteers, with amazing results.
CLOSE FLYBYS
Other recent close passes also revealed volcanic activity, including this JunoCam image from late last year:
NASA / JPL-Caltech / SwRI
Io, which is a little larger than Earth's Moon, is the most geologically active world in the solar system. Its core gets a real workout from Jupiter's enormous gravitational field, whose tidal forces heat the moon's interior. The volcanoes in turn spew energetic charged particles into the powerful Io plasma torus, which connects via magnetic field lines back to Jupiter, creating a complex, interactive system.
JunoCam was actually impacted radiation exposure during the December 30th perijove pass. Engineers used a method known as 'annealing' to use internal heaters on the camera to warm it up and repair the imager for this month's pass.
JUNO'S END PHASE
The Juno mission has thus far spent over seven years at Jupiter, working as the first solar-powered mission in the outer solar system. For most of its mission, Juno has stayed well out of range of the major moons, for safety reasons. The primary mission was to measure Jupiter’s magnetic field and interior, something Juno could do safely from a distance.
Now, though, a series of close passes have shortened Juno's orbit, bringing it down to 33 days. That puts the probe ever closer to Jupiter and its potentially lethal radiation, but also in scientifically interesting regions.
NASA/JPL-Caltech/SwRI
As of this writing, Juno is funded through September 2025. Ultimately, Juno won't share the same fate as the Galileo mission, which burned up in the Jovian atmosphere... such a final deposal orbit is unnecessary, as Juno is now safely within the interior of Europa and cannot contaminate the icy moon. Instead, Juno will spend its days derelict, until it either burns up in the atmosphere of Jupiter or impacts a small interior moon.
Juno is currently the only mission active at Jupiter, but ESA’s Jupiter Icy Moons (JUICE) mission launched just last year and will arrive at Jupiter in 2031. NASA’s Europa Clipper, set to launch on a Falcon Heavy rocket on October 10th, will beat JUICE to Jupiter, arriving in 2030.
In the meantime, we’ll ride with Juno for one more year of awe-inspiring exploration.
Quelle: Sky&Telescope
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Update: 8.02.2024
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Jupiter's volcanic moon Io looks outstanding in these close flyby photos from NASA's Juno probe
The images Juno captured of the scene are absolutely amazing.
NASA's Juno spacecraft has now paid Jupiter's moon Io its second close-up visit in less than two Earth months. (Image credit: NASA)
NASA's Juno spacecraft has now paid Jupiter's moon Io its second close-up visit in less than two Earth months.
To mark the rendezvous, NASA and the Southwest Research Institute released a new batch of images showing the infamously infernal moon in a state of seemingly uncharacteristic calm. Scientists also released a video showing Juno's gradual approach to the Jovian satellite — a sphere pockmarked with points of light from volcanic eruptions.
Juno launched in 2011 and entered orbit around Jupiter in 2016. Each orbit takes Juno on a highly elliptical loop, allowing it to tread closely around Jupiter's poles before circling farther away from the planet. The spacecraft's Jupiter-related task list was originally completed in 2021, but NASA extended the mission with an eye on exploring some of the world's larger moons.
Io is one of those moons. The spacecraft first passed within 930 miles (1,500 kilometers) of the moon in Dec. 2023, coming closer than any craft ever had, save for NASA's Galileo spacecraft in 2001. And, over the past several days, Juno managed to complete its 58th orbit, meaning the spacecraft has now taken a second pass at that distance.
Io has the misfortune of being an object in a great gravitational game, as both colossal Jupiter and its moon Europa pull at Io's interior and churn it into a hotbed of volcanic activity. But we don't quite know what this process actually looks like. Some scientists, for example, believe Io holds a global magma ocean beneath the surface. Others think that a superhot core of solid metal drives the volcanoes.
By using Juno to examine Io, Juno's scientists hope they can determine how exactly the planet and its volcanoes tick.
Juno's extended mission will now take it up to September 2025. If another extension is not in the cards, its operators will deorbit it into the gas giant's atmosphere.
Quelle: SC
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Update: 9.02.2024
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For Your Processing Pleasure: The Sharpest Pictures of Jupiter’s Volcanic Moon Io in a Generation
Jupiter's moon Io, its night side illuminated by reflected sunlight from Jupiter, or "Jupitershine."
Image data: NASA/JPL-Caltech/SwRI/MSSS Image processing by Emma Wälimäki © CC BY
On Dec. 30th, 2023, Juno came within about 930 miles (1,500 kilometers) of the surface of the solar system’s most volcanic world. It made a second ultra-close flyby of Io just this week. The second pass went predominantly over the southern hemisphere of Io, while prior flybys have been over the north. There’s a lot to see in these photos! There’s evidence of an active plume, tall mountain peaks with well-defined shadows, and lava lakes—some with apparent islands.
It will be a challenge to sort all of this out, and the JunoCam scientists need your help. Previous JunoCam volunteers like Gerald Eichstadt have seen their processed images appear in multiple scientific publications and press releases.
Quelle: NASA
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Update: 6.03.2023
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NASA’s Juno Mission Measures Oxygen Production at Europa
This illustration shows charged particles from Jupiter impacting Europa’s surface, splitting frozen water molecules into oxygen and hydrogen molecules. Scientists believe some of these newly created oxygen gases could migrate toward the moon’s subsurface ocean, as depicted in the inset image.
Credit: NASA/JPL-Caltech/SWRI/PU
The ice-covered Jovian moon generates 1,000 tons of oxygen every 24 hours – enough to keep a million humans breathing for a day.
Scientists with NASA’s Juno mission to Jupiter have calculated the rate of oxygen being produced at the Jovian moon Europa to be substantially less than most previous studies. Published on March 4 in Nature Astronomy, the findings were derived by measuring hydrogen outgassing from the icy moon’s surface using data collected by the spacecraft’s Jovian Auroral Distributions Experiment (JADE) instrument.
The paper’s authors estimate the amount of oxygen produced to be around 26 pounds every second (12 kilograms per second). Previous estimates range from a few pounds to over 2,000 pounds per second (over 1,000 kilograms per second). Scientists believe that some of the oxygen produced in this manner could work its way into the moon’s subsurface ocean as a possible source of metabolic energy.
With an equatorial diameter of 1,940 miles (3,100 kilometers), Europa is the fourth largest of Jupiter’s 95 known moons and the smallest of the four Galilean satellites. Scientists believe a vast internal ocean of salty water lurks beneath its icy crust, and they are curious about the potential for life-supporting conditions to exist below the surface.
It is not just the water that has astrobiologists’ attention: The Jovian moon’s location plays an important role in biological possibilities as well. Europa’s orbit places it right in the middle of the gas giant’s radiation belts. Charged, or ionized, particles from Jupiter bombard the icy surface, splitting water molecules in two to generate oxygen that might find its way into the moon’s ocean.
“Europa is like an ice ball slowly losing its water in a flowing stream. Except, in this case, the stream is a fluid of ionized particles swept around Jupiter by its extraordinary magnetic field,” said JADE scientist Jamey Szalay from Princeton University in New Jersey. “When these ionized particles impact Europa, they break up the water-ice molecule by molecule on the surface to produce hydrogen and oxygen. In a way, the entire ice shell is being continuously eroded by waves of charged particles washing up upon it.”
Capturing the Bombardment
As Juno flew within 220 miles (354 kilometers) of Europa at 2:36 p.m. PDT Sept. 29, 2022, JADE identified and measured hydrogen and oxygen ions that had been created by the bombarding charged particles and then “picked up” by Jupiter’s magnetic field as it swept past the moon.
“Back when NASA’S Galileo mission flew by Europa, it opened our eyes to the complex and dynamic interaction Europa has with its environment. Juno brought a new capability to directly measure the composition of charged particles shed from Europa’s atmosphere, and we couldn’t wait to further peek behind the curtain of this exciting water world,” said Szalay. “But what we didn’t realize is that Juno’s observations would give us such a tight constraint on the amount of oxygen produced in Europa’s icy surface.”
Juno carries 11 state-of-the-art science instruments designed to study the Jovian system, including nine charged-particle and electromagnetic-wave sensors for studying Jupiter’s magnetosphere.
“Our ability to fly close to the Galilean satellites during our extended mission allowed us to start tackling a breadth of science, including some unique opportunities to contribute to the investigation of Europa’s habitability,” said Scott Bolton, Juno’s principal investigator from the Southwest Research Institute in San Antonio. “And we’re not done yet. More moon flybys and the first exploration of Jupiter’s close ring and polar atmosphere are yet to come.”
Oxygen production is one of many facets that NASA’s Europa Clipper mission will investigate when it arrives at Jupiter in 2030. The mission has a sophisticated payload of nine science instruments to determine if Europa has conditions that could be suitable for life.
Now Bolton and the rest of the Juno mission team are setting their sights on another Jovian world, the volcano-festooned moon Io. On April 9, the spacecraft will come within about 10,250 miles (16,500 kilometers) of its surface. The data Juno gathers will add to findings from past Io flybys, including two extremely close approaches of about 932 miles (1,500 kilometers) on Dec. 30, 2023, and Feb. 3, 2024.
Quelle: NASA
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Update: 8.03.2024
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JUNO SPACECRAFT MEASURES OXYGEN PRODUCTION ON JUPITER’S MOON, EUROPA
NASA’s Juno spacecraft has directly measured charged oxygen and hydrogen molecules from the atmosphere of one of Jupiter’s largest moons, Europa. According to a new study co-authored by SwRI scientists and led by Princeton University, these observations provide key constraints on the potential oxygenation of its subsurface ocean.
“These findings have direct implications on the potential habitability of Europa,” said Juno Principal Investigator Dr. Scott Bolton of SwRI, a co-author of the study. “This study provides the first direct in-situ measurement of water components existing in Europa’s atmosphere, giving us a narrow range that could support habitability.”
In 2022, Juno completed a flyby of Europa, coming as close as 352 kilometers to the moon. The SwRI-developed Jovian Auroral Distributions Experiment (JADE) instrument aboard Juno detected significant amounts of charged molecular oxygen and hydrogen lost from the atmosphere.
“For the first time, we’ve been able to definitively detect hydrogen and oxygen with in-situ measurements and further confirm that Europa’s atmosphere is made primarily of hydrogen and oxygen molecules,” said SwRI Staff Scientist and co-author Dr. Robert Ebert.
The source of these molecules is thought to be water ice on Europa’s surface. Jupiter’s rampant radiation breaks H2O’s molecular bonds, leaving behind oxygen and hydrogen. The heavier oxygen molecules remain more constrained to the surface, or near-surface atmosphere, while the lighter-weight hydrogen predominately escapes into the atmosphere and beyond. Oxygen produced in the ice is either lost from the atmosphere and/or sequestered in the surface. Oxygen retained in Europa’s ice may work its way to its subsurface ocean as a possible source of metabolic energy.
“Europa’s ice shell absorbs radiation, protecting the ocean underneath. This absorption also produces oxygen within the ice, so in a way, the ice shell acts as Europa’s lung, providing a potential oxygen source for the ocean.” said Princeton University Research Scholar Dr. Jamey Szalay, the study’s lead author. “We put narrow constraints on the total oxygen production at Europa currently at around 12 kg per second. Before Juno, previous estimates ranged from a few kg per second to over 1,000 kg per second. The findings unambiguously demonstrate oxygen is continuously produced in the surface, just a good bit lower than we expected.”
“We designed JADE to measure the charged particles that create Jupiter’s auroras,” said SwRI Staff Scientist and co-author Dr. Frederic Allegrini. “Flybys of Europa were not part of the primary Juno mission. JADE was designed to work in a high-radiation environment but not necessarily Europa’s environment, which is constantly bombarded with high levels of radiation. Nonetheless, the instrument performed beautifully.”
The new measurements contribute to a greater understanding of Europa and its environment, and they open the door for newer, more precise models. The study’s new estimation of how much oxygen is produced within Europa’s surface, for instance, could inform future research related to its subsurface ocean and potential habitability. As these observations provide the first charged particle composition measurements within Europa’s vicinity, they provide an important new window into the moons’ complex interaction with its environment.
“Europa is a fascinating object because scientists are confident a liquid ocean exists in its interior,” Ebert said. “Water is important for the existence of life and can be found in or on objects with varying characteristics. Europa is a good place to search for water within our solar system.”
The paper “Oxygen production from dissociation of Europa’s water ice surface,” appears in Nature Astronomy: https://www.nature.com/articles/s41550-024-02206-x(link is external)
Quelle: Southwest Research Institute
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Update: 20.04.2024
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NASA’s Juno Gives Aerial Views of Mountain, Lava Lake on Io
Imagery from the solar-powered spacecraft provides close-ups of intriguing features on the hellish Jovian moon.
This animation is an artist’s concept of Loki Patera, a lava lake on Jupiter’s moon Io, made using data from the JunoCam imager aboard NASA’s Juno spacecraft. With multiple islands in its interior, Loki is a depression filled with magma and rimmed with molten lava.
Credit: NASA/JPL-Caltech/SwRI/MSSS
Scientists on NASA’s Juno mission to Jupiter have transformed data collected during two recent flybys of Io into animations that highlight two of the Jovian moon’s most dramatic features: a mountain and an almost glass-smooth lake of cooling lava. Other recent science results from the solar-powered spacecraft include updates on Jupiter’s polar cyclones and water abundance.
The new findings were announced Wednesday, April 16, by Juno’s principal investigator Scott Bolton during a news conference at the European Geophysical Union General Assembly in Vienna.
Juno made extremely close flybys of Io in December 2023 and February 2024, getting within about 930 miles (1,500 kilometers) of the surface, obtaining the first close-up images of the moon’s northern latitudes.
“Io is simply littered with volcanoes, and we caught a few of them in action,” said Bolton. “We also got some great close-ups and other data on a 200-kilometer-long (127-mile-long) lava lake called Loki Patera. There is amazing detail showing these crazy islands embedded in the middle of a potentially magma lake rimmed with hot lava. The specular reflection our instruments recorded of the lake suggests parts of Io’s surface are as smooth as glass, reminiscent of volcanically created obsidian glass on Earth.”
The JunoCam instrument on NASA’s Juno captured this view of Jupiter’s moon Io — with the first-ever image of its south polar region — during the spacecraft’s 60th flyby of Jupiter on April 9.
Credit: Image credit: NASA/JPL-Caltech/SwRI/MSSS. Image processing: Gerald Eichstädt/Thomas Thomopoulos (CC BY)
Maps generated with data collected by Juno’s Microwave Radiometer (MWR) instrument reveal Io not only has a surface that is relatively smooth compared to Jupiter’s other Galilean moons, but also has poles that are colder than middle latitudes.
Pole Position
During Juno’s extended mission, the spacecraft flies closer to the north pole of Jupiter with each pass. This changing orientation allows the MWR instrument to improve its resolution of Jupiter’s northern polar cyclones. The data allows multiwavelength comparisons of the poles, revealing that not all polar cyclones are created equal.
“Perhaps most striking example of this disparity can be found with the central cyclone at Jupiter’s north pole,” said Steve Levin, Juno’s project scientist at NASA’s Jet Propulsion Laboratory in Southern California. “It is clearly visible in both infrared and visible light images, but its microwave signature is nowhere near as strong as other nearby storms. This tells us that its subsurface structure must be very different from these other cyclones. The MWR team continues to collect more and better microwave data with every orbit, so we anticipate developing a more detailed 3D map of these intriguing polar storms.”
Jovian Water
One of the mission’s primary science goals is to collect data that could help scientists better understand Jupiter’s water abundance. To do this, the Juno science team isn’t hunting for liquid water. Instead, they are looking to quantify the presence of oxygen and hydrogen molecules (the molecules that make up water) in Jupiter’s atmosphere. An accurate estimate is critical to piecing together the puzzle of our solar system’s formation.
Jupiter was likely the first planet to form, and it contains most of the gas and dust that wasn’t incorporated into the Sun. Water abundance also has important implications for the gas giant’s meteorology (including how wind currents flow on Jupiter) and internal structure.
In 1995, NASA’s Galileo probe provided an early dataset on Jupiter’s water abundance during the spacecraft’s 57-minute descent into the Jovian atmosphere. But the data created more questions than answers, indicating the gas giant’s atmosphere was unexpectedly hot and — contrary to what computer models had indicated — bereft of water.
“The probe did amazing science, but its data was so far afield from our models of Jupiter’s water abundance that we considered whether the location it sampled could be an outlier. But before Juno, we couldn’t confirm,” said Bolton. “Now, with recent results made with MWR data, we have nailed down that the water abundance near Jupiter’s equator is roughly three to four times the solar abundance when compared to hydrogen. This definitively demonstrates that the Galileo probe’s entry site was an anomalously dry, desert-like region.”
The results support the belief that the during formation of our solar system, water-ice material may have been the source of the heavy element enrichment (chemical elements heavier than hydrogen and helium that were accreted by Jupiter) during the gas giant’s formation and/or evolution. The formation of Jupiter remains puzzling, because Juno results on the core of the gas giant suggest a very low water abundance — a mystery that scientists are still trying to sort out.
Data during the remainder of Juno’s extended mission may help, both by enabling scientists to compare Jupiter’s water abundance near the polar regions to the equatorial region and by shedding additional light on the structure of the planet’s dilute core.
During Juno’s most recent flyby of Io, on April 9, the spacecraft came within about 10,250 miles (16,500 kilometers) of the moon’s surface. It will execute its 61st flyby of Jupiter on May 12.
More About the Mission
NASA’s Jet Propulsion Laboratory, a division of Caltech in Pasadena, California, manages the Juno mission for the principal investigator, Scott Bolton, of the Southwest Research Institute in San Antonio. Juno is part of NASA’s New Frontiers Program, which is managed at NASA’s Marshall Space Flight Center in Huntsville, Alabama, for the agency’s Science Mission Directorate in Washington. The Italian Space Agency (ASI) funded the Jovian InfraRed Auroral Mapper. Lockheed Martin Space in Denver built and operates the spacecraft.
Quelle: NASA
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Jupiter's moon Io has been a volcanic inferno for billions of years
Measurements of sulphur isotopes in Io’s atmosphere show that the moon may have been volcanically active for its entire lifetime
Io, Jupiter’s innermost moon, is the most volcanically active body in the solar system
Jupiter’s moon Io has been continuously remodelled by volcanic eruptions for billions of years, possibly since it first formed.
Io is the most volcanically active body in the solar system, spewing plumes of sulphurous material from its many volcanoes, which can be seen from Earth. Astronomers know that this is currently driven by so-called tidal heating as the gravity of Jupiter and nearby moons deforms Io, but it was unclear if that was always the case or whether there had been a calmer past.
Now, Katherine de Kleer at the California Institute of Technology and her colleagues have found that Io has probably been blasting out lava for almost its entire history. They did this by measuring the ratio of two isotopes of sulphur in its atmosphere.
Sulphur’s most common stable form contains 16 protons and 16 neutrons in each atom, but a heavier stable form called sulphur-34 has two extra neutrons. On Io, volcanoes are constantly spewing both isotopes into its atmosphere and onto its surface. The very top layer of its atmosphere, which contains more of the lighter sulphur atoms, is lost to space as the moon travels around Jupiter, which changes the ratio of these isotopes.
De Kleer and her colleagues used observations from the Atacama Large Millimeter/submillimeter Array (ALMA), a set of radio telescopes in Chile, to measure the ratio in Io’s atmosphere. Then, by modelling how much sulphur Io might be losing each year, the team could work back to find out when Io’s sulphur ratio looked like the rest of the solar system. Although they can’t say exactly how long it has been volcanically active, it appears to have been erupting for between 2.5 and 4 billion years.
Because Io’s volcanism is down to tidal heating by Jupiter and its other moons, like Europa and Ganymede, the results can also be used to infer the arrangement of the Jovian system billions of years ago. “Io’s longevity of volcanism directly reflects how long this orbital configuration has been present,” says de Kleer.
If Io has been consistently volcanic for billions of years, then this also means it will have recycled its deeper geological layers many times over, says Lionel Wilson at Lancaster University in the UK.
This presents a rare opportunity to find out about the chemical makeup of Io’s deeper layers, such as the mantle that lies below its outer crust, by sampling the material that is blasting out, he says. “If these volcanoes have been erupting for the whole solar system history, essentially, then it’s safe to look at the composition of what’s coming out and know that that’s really a snapshot of the entire mantle of Io,” says Wilson.
Quelle: NewScientist
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Update: 15.05.2024
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NASA’s Juno Mission Spots Jupiter’s Tiny Moon Amalthea
NASA’s Juno mission captured these views of Jupiter during its 59th close flyby of the giant planet on March 7, 2024. They provide a good look at Jupiter’s colorful belts and swirling storms, including the Great Red Spot. Close examination reveals something more: two glimpses of the tiny moon Amalthea (see Figure B below).
Figure B
NASA’s Juno mission captured these views of Jupiter during its 59th close flyby of the giant planet on March 7, 2024. They provide a good look at Jupiter’s colorful belts and swirling storms, including the Great Red Spot. Close examination reveals something more: two glimpses of the tiny moon Amalthea.
Image data: NASA/JPL-Caltech/SwRI/MSSS. Image processing by Gerald Eichstädt
With a radius of just 52 miles (84 kilometers), Amalthea has a potato-like shape, lacking the mass to pull itself into a sphere. In 2000, NASA’s Galileo spacecraft revealed some surface features, including impact craters, hills, and valleys. Amalthea circles Jupiter inside Io’s orbit, which is the innermost of the planet’s four largest moons, taking 0.498 Earth days to complete one orbit.
Amalthea is the reddest object in the solar system, and observations indicate it gives out more heat than it receives from the Sun. This may be because, as it orbits within Jupiter’s powerful magnetic field, electric currents are induced in the moon’s core. Alternatively, the heat could be from tidal stresses caused by Jupiter’s gravity.
At the time that the first of these two images was taken, the Juno spacecraft was about 165,000 miles (265,000 kilometers) above Jupiter’s cloud tops, at a latitude of about 5 degrees north of the equator.
Citizen scientist Gerald Eichstädt made these images using raw data from the JunoCam instrument, applying processing techniques to enhance the clarity of the images.
Quelle: NASA
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Update: 17.05.2024
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NASA’s Juno Provides High-Definition Views of Europa’s Icy Shell
Jupiter’s moon Europa was captured by the JunoCam instrument aboard NASA’s Juno spacecraft during the mission’s close flyby on Sept. 29, 2022. The images show the fractures, ridges, and bands that crisscross the moon’s surface.
Credit: Image data: NASA/JPL-Caltech/SwRI/MSSS. Image processing: Björn Jónsson (CC BY 3.0)
Imagery from the solar-powered spacecraft shows some intriguing features on the ice-encased Jovian moon.
Images from the JunoCam visible-light camera aboard NASA’s Juno spacecraft supports the theory that the icy crust at the north and south poles of Jupiter’s moon Europa is not where it used to be. Another high-resolution picture of the icy moon, by the spacecraft’s Stellar Reference Unit (SRU), reveals signs of possible plume activity and an area of ice shell disruption where brine may have recently bubbled to the surface.
The JunoCam results recently appeared in the Planetary Science Journal and the SRU results in the journal JGR Planets.
On Sept. 29, 2022, Juno made its closest flyby of Europa, coming within 220 miles (355 kilometers) of the moon’s frozen surface. The four pictures taken by JunoCam and one by the SRU are the first high-resolution images of Europa since Galileo’s last flyby in 2000.
True Polar Wander
Juno’s ground track over Europa allowed imaging near the moon’s equator. When analyzing the data, the JunoCam team found that along with the expected ice blocks, walls, scarps, ridges, and troughs, the camera also captured irregularly distributed steep-walled depressions 12 to 31 miles (20 to 50 kilometers) wide. They resemble large ovoid pits previously found in imagery from other locations of Europa.
A giant ocean is thought to reside below Europa’s icy exterior, and these surface features have been associated with “true polar wander,” a theory that Europa’s outer ice shell is essentially free-floating and moves.
“True polar wander occurs if Europa’s icy shell is decoupled from its rocky interior, resulting in high stress levels on the shell, which lead to predictable fracture patterns,” said Candy Hansen, a Juno co-investigator who leads planning for JunoCam at the Planetary Science Institute in Tucson, Arizona. “This is the first time that these fracture patterns have been mapped in the southern hemisphere, suggesting that true polar wander’s effect on Europa’s surface geology is more extensive than previously identified.”
Quelle: NASA
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Update: 22.07.2024
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NASA's Juno Mission Captures Dynamic Cloud Patterns on Jupiter
During its 61st close flyby of Jupiter on May 12, 2024, NASA's Juno spacecraft captured a stunning color-enhanced view of the giant planet's northern hemisphere. This detailed image showcases the chaotic clouds and cyclonic storms in an area scientists refer to as a folded filamentary region. In these zones, the zonal jets responsible for Jupiter's banded cloud patterns break down, resulting in rapidly evolving turbulent patterns and cloud structures over a matter of days.
Citizen scientist Gary Eason created this remarkable image using raw data from the JunoCam instrument, employing digital processing techniques to enhance its color and clarity.
At the time the raw image was taken, the Juno spacecraft was approximately 18,000 miles (29,000 kilometers) above Jupiter's cloud tops, positioned at a latitude of about 68 degrees north of the equator.
JunoCam's raw images are available to the public for exploration and processing into final image products at https://missionjuno.swri.edu/junocam/processing. For more information on NASA's citizen science programs, visit https://science.nasa.gov/citizenscience and https://www.nasa.gov/solve/opportunities/citizenscience.
Juno, launched in 2011, aims to understand Jupiter's origins, structure, atmosphere, and magnetosphere by conducting long-term close-up observations. Since entering Jupiter's orbit in 2016, Juno has provided unprecedented insights into the planet's dynamics. The spacecraft's suite of scientific instruments has allowed researchers to peer below the cloud cover, revealing the complexities of Jupiter's atmospheric conditions and magnetic field.
The folded filamentary regions, observed in this flyby, are particularly intriguing to scientists. These areas show the interplay of different atmospheric forces that create the planet's distinct cloud formations and weather patterns. By studying these regions, researchers hope to gain a deeper understanding of the mechanisms driving Jupiter's atmospheric behavior.
Juno's findings have broad implications beyond Jupiter. By comparing the gas giant's atmospheric phenomena with those observed on other planets, including Earth, scientists can refine their models of atmospheric dynamics and improve predictions of weather and climate systems.
More information about Juno can be found at https://www.nasa.gov/juno and https://missionjuno.swri.edu. For detailed findings and other scientific results from the Juno mission, visit https://www.missionjuno.swri.edu/science-findings.
Quelle: SD
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