New discoveries by the James Webb Space Telescope have unveiled secrets about Jupiters biggest moon, Ganymede, and the most volcanically active one, Io. The findings include evidence of the peroxide being produced by charged particles impacting the ice on Ganymede, and brand-new observations of ongoing eruptions on Io. Credit: Ganymede: Samantha Trumbo, Cornell; Io: Imke de Pater, UC Berkeley
The observations can only be made when Io is in Jupiters shadow, when it is simpler to see the radiant SO gases. When Io is in Jupiters shadow, the SO2 gas in Ios environment freezes out onto its surface area, leaving just SO and freshly produced volcanic SO2 gas in the atmosphere.
” This reveals that we can do incredible science with the James Webb Space Telescope on solar system objects, even if the object is really extremely bright, like Jupiter, but likewise when you take a look at very faint things next to Jupiter,” stated Imke de Pater, professor emerita of astronomy and earth and planetary science at the University of California, Berkeley. De Pater and Thierry Fouchet from the Paris Observatory are co-principal investigators for the Early Release Science planetary system observation group, one of 13 teams offered early access to the telescope.
A spectroscopic map of Ganymede stemmed from JWST measurements reveals light absorption around the poles quality of the particle hydrogen peroxide. The circle describes the surface areas of the moon. Credit: Samantha Trumbo, Cornell
Ganymedes Hydrogen Peroxide Study
Samantha Trumbo, a 51 Pegasi b postdoctoral fellow at Cornell University, led the study of Ganymede, which was released on July 21 in the journal Science Advances. Using measurements caught by the near infrared spectrometer (NIRSpec) on JWST, the team spotted the absorption of light by hydrogen peroxide– H2O2– around the north and south poles of the moon, an outcome of charged particles around Jupiter and Ganymede affecting the ice that blankets the moon.
” JWST exposing the existence of hydrogen peroxide at Ganymedes poles shows for the first time that charged particles funneled along Ganymedes electromagnetic field are preferentially changing the surface area chemistry of its polar caps,” Trumbo stated.
The astronomers argue that the peroxide is produced by charged particles hitting the frozen water ice around the poles and breaking the water molecules into pieces– a procedure called radiolysis– which then recombine to form H2O2. They thought that radiolysis would take place primarily around the poles on Ganymede because, unlike all other moons in our planetary system, it has an electromagnetic field that directs charged particles toward the poles.
Closeup images of Ganymede (left), taken by NASAs Juno spacecraft in 2021, and Io (ideal), taken by NASAs Galileo spacecraft in 1997. Credit: NASA/JPL/USGS
Magnetic Field and Comparison with Europa
” Just like how Earths magnetic field directs charged particles from the sun to the highest latitudes, causing the aurora, Ganymedes electromagnetic field does the very same thing to charged particles from Jupiters magnetosphere,” she added. “Not just do these particles lead to aurorae at Ganymede, as well, however they likewise impact the icy surface.”
Trumbo and Michael Brown, professor of planetary astronomy at Caltech, where Trumbo just recently got her Ph.D., had actually previously studied hydrogen peroxide on Europa, another of Jupiters 4 Galilean satellites. On Europa, however, the peroxide was noticeable over much of the surface, perhaps, in part, due to the fact that it has no magnetic field to secure the surface from the fast-moving particles zipping around Jupiter.
Ramifications for Outer Solar System
” This is likely a truly essential and prevalent procedure,” Trumbo said. “These observations of Ganymede provide a key window to comprehend how such water radiolysis might drive chemistry on icy bodies throughout the outer solar system, consisting of on surrounding Europa and Callisto (the fourth Galilean moon).”.
” It assists to in fact comprehend how this so-called radiolysis works which, undoubtedly, it works as individuals expected, based on lab experiments in the world,” de Pater stated.
A JWST infrared picture of Io reveals hot volcanic eruptions at Kanehekili Fluctus (center) and Loki Patera (ideal). The circle describes the surface of the moon. Credit: Imke de Pater, UC Berkeley.
Ios Sulfurous Environment.
In a second paper, accepted for publication in the journal JGR: Planets, a publication of the American Geophysical Union, de Pater and her associates report brand-new Webb observations of Io that reveal numerous continuous eruptions, including a brightening at a volcanic complex called Loki Patera and an incredibly brilliant eruption at Kanehekili Fluctus. Since Io is the only volcanically active moon in the planetary system– Jupiters gravitational push and pull heats it up– studies like this provide planetary scientists a different viewpoint than can be gotten by studying volcanos on Earth.
For the very first time, the researchers were able to connect a volcanic eruption– at Kanehekili Fluctus– to a particular emission line, a so-called “forbidden” line, of the gas sulfur monoxide (SO).
Thermal infrared measurements (left) show a lightening up of Kanekehili Fluctus, a big and, throughout the observation period, very active volcanic area on Io. Credit: Chris Moeckel and Imke de Pater, UC Berkeley; Io map courtesy of USGS.
Understanding Ios Atmosphere.
Sulfur dioxide (SO2) is the main component of Ios atmosphere, originating from sublimation of SO2 ice, as well as ongoing volcanic eruptions, similar to the production of SO2 by volcanos on Earth. The volcanos also produce SO, which is much more difficult to identify than SO2. In particular, the forbidden SO emission line is very weak due to the fact that SO remains in such low concentrations and produced for just a short time after being excited. The observations can only be made when Io is in Jupiters shadow, when it is much easier to see the glowing SO gases. When Io is in Jupiters shadow, the SO2 gas in Ios environment freezes out onto its surface area, leaving just SO and freshly released volcanic SO2 gas in the atmosphere.
Connection in between SO and Volcanoes.
” These observations with Webb show for the first time that the SO in fact did come from a volcano,” de Pater stated.
De Pater had made previous observations of Io with the Keck Telescope in Hawaii and found low levels of the forbidden SO emission over much of the moon, however she was not able to connect SO hotspots specifically to an active volcano. She believes that much of this SO, in addition to the SO2 seen during an eclipse, is originating from so-called stealth volcanoes, which erupt gas however not dust, which would make them noticeable.
Twenty years ago, de Pater and her group proposed that this thrilled state of SO could just be produced in hot volcanic vents, which the rare environment permitted this state to stick around long enough– a few seconds– to produce the prohibited line. Usually, fired up states that produce this emission are rapidly damped out by crashes with other molecules in the environment and never seen. Just in parts of the atmosphere where the gas is sporadic do such fired up states last long enough to emit forbidden lines. The greens and reds of Earths auroras are produced by forbidden transitions of oxygen in the tenuous upper atmosphere.
More Observations and Concluding Remarks.
” The link between SO and volcanoes connect a hypothesis we had in 2002 to describe how we could see SO emission at all,” she stated. “The only method we could discuss this emission is if the SO is excited in the volcanic vent at a temperature of 1500 Kelvin or two, and that it comes out in this thrilled state, loses its photon within a couple of seconds, which is the emission we see. These observations are the very first that actually show that this is the most likely mechanism of why we see that SO.”.
Webb will observe Io once again in August with NIRSpec. The approaching observation and the earlier one, which occurred on Nov. 15, 2022, were taken when Io was in the shadow of Jupiter so that light reflected from the world did not overwhelm the light coming from Io.
De Pater kept in mind, too, that the brightening of Loki Patera was constant with the observed duration of eruptions at the volcano, which brighten, on average, about every 500 Earth days, with the lightening up lasting for a number of months. She determined this since it was not intense when she observed the moon with Keck in August and September 2022, nor was it brilliant when another astronomer observed it from April through July 2022. Just the JWST captured the occasion.
” The Webb observations showed that really eruptions had started, which it was much brighter than what we had actually seen in September,” she stated.
While De Pater is mainly focused on the Jovian system– its rings, little moons and the larger moons Ganymede and Io– she and other members of the early science team of some 80 astronomers are also using JWST to study the planetary systems of Saturn, Uranus and Neptune.
References:.
” Hydrogen peroxide at the poles of Ganymede” by Samantha K. Trumbo, Michael E. Brown, Dominique Bockelée-Morvan, Imke de Pater, Thierry Fouchet, Michael H. Wong, Stéphanie Cazaux, Leigh N. Fletcher, Katherine de Kleer, Emmanuel Lellouch, Alessandro Mura, Olivier Poch, Eric Quirico, Pablo Rodriguez-Ovalle, Mark R. Showalter, Matthew S. Tiscareno and Federico Tosi, 21 July 2023, Science Advances.DOI: 10.1126/ sciadv.adg3724.
” An Energetic Eruption With Associated SO 1.707 Micron Emissions at Ios Kanehekili Fluctus and a Brightening Event at Loki Patera Observed by JWST” by Imke de Pater, Emmanuel Lellouch, Darrell F. Strobel, Katherine de Kleer, Thierry Fouchet, Michael H. Wong, Bryan J. Holler, John Stansberry, Patrick M. Fry, Michael E. Brown, Dominique Bockelée-Morvan, Samantha K. Trumbo, L. N. Fletcher, Matthew M. Hedman, Edward M. Molter, Mark Showalter, Matthew S. Tiscareno, Stéphanie Cazaux, Ricardo Hueso, Statia Luszcz-Cook, Henrik Melin, Chris Moeckel, Alessandro Mura, Glenn Orton, Lorenz Roth, Joachim Saur, Federico Tosi, 18 July 2023, JGR: Planets.DOI: 10.1029/ 2023JE007872.
New discoveries by the James Webb Space Telescope have revealed secrets about Jupiters biggest moon, Ganymede, and the most volcanically active one, Io. The findings consist of proof of the peroxide being produced by charged particles impacting the ice on Ganymede, and brand-new observations of continuous eruptions on Io. Credit: Ganymede: Samantha Trumbo, Cornell; Io: Imke de Pater, UC Berkeley
Groundbreaking observations by the James Webb Space Telescope have revealed hydrogen peroxide on Ganymede and ongoing volcanic eruptions on Io, boosting our understanding of Jupiters moons and the wider solar system.
With its delicate infrared electronic cameras and high-resolution spectrometer, the James Webb Space Telescope (JWST) is exposing new secrets of Jupiters Galilean satellites, in particular Ganymede, the biggest moon, and Io, the most volcanically active.
In two separate publications, astronomers who are part of JWSTs Early Release Science program report the very first detection of hydrogen peroxide on Ganymede and sulfurous fumes on Io, both the outcome of Jupiters domineering influence.
