A5041214093- Astro and Planetary Science
- Geomagnetism and Paleomagnetism Studies
- Ionosphere and magnetosphere dynamics
- Solar and Space Plasma Dynamics
- Planetary Science and Exploration
- Space Exploration and Technology
- Stellar, planetary, and galactic studies
- Scientific Research and Discoveries
- Astronomical Observations and Instrumentation
- History and Developments in Astronomy
- Nuclear physics research studies
- Gamma-ray bursts and supernovae
- High-pressure geophysics and materials
- Historical Astronomy and Related Studies
- Malaria Research and Control
- Advanced Neural Network Applications
- Remote Sensing and LiDAR Applications
- Automated Road and Building Extraction
- Classical Philosophy and Thought
- Drug-Induced Hepatotoxicity and Protection
- Space Satellite Systems and Control
- Urban Heat Island Mitigation
- Geology and Paleoclimatology Research
- Classical Antiquity Studies
- Scientific Computing and Data Management
Institut Scientifique de Service Public
2023-2025
University of Liège
2014-2023
John Wiley & Sons (United States)
2019
Charles River Laboratories (Netherlands)
2019
Max Planck Society
2014-2018
Max Planck Institute for Solar System Research
2014-2018
Abstract A large set of observations Jupiter's ultraviolet aurora was collected with the Hubble Space Telescope concurrently NASA‐Juno mission, during an eight‐month period, from 30 November 2016 to 18 July 2017. These cover Juno orbits 3 7 which in situ and remote sensing instruments, as well other observatories, obtained a wealth unprecedented information on magnetosphere connection its auroral ionosphere. is known vary rapidly, timescales ranging seconds one Jovian rotation. The main...
Although mass and energy in Jupiter's magnetosphere mostly come from the innermost Galilean moon Io's volcanic activities, solar wind perturbations can play crucial roles releasing magnetospheric powering aurorae polar regions. The systematic response of aurora to compression remains poorly understood. Here we report analysis a set auroral images with contemporaneous situ magnetopause detections. We distinguish two types enhancements: transient localized one long-lasting global one. show...
Abstract Dawn storms are among the brightest events in Jovian aurorae. Up to now, they had only been observed from Earth‐based observatories, showing Sun‐facing side of planet. Here, we show for first time global views phenomenon, its initiation end and nightside aurora onto dayside. Based on Juno's 20 orbits, some patterns now emerge. Small short‐lived spots often seen a couple hours before main emission starts brighten evolve straight arc more irregular one midnight sector. As whole...
Abstract We present simultaneous observations of aurorae at Jupiter from the Hubble Space Telescope and Hisaki, in combination with situ measurements magnetic field, particles, radio waves Juno Spacecraft outer magnetosphere, ~ 80 R J to 60 during 17 22 March 2017. Two cycles accumulation release flux, named loading/unloading, were identified this period, which correlate well electron energization auroral intensifications. Magnetic reconnection events are both loading unloading periods,...
In Cameroon, like in other African countries, infusions of Artemisia afra and annua are widely used for the management health-related problems, including malaria. The secondary metabolite contents medicinal plants vary between different geographical regions seasons, directly influencing their effectiveness treating ailments. This study explores phytochemical diversity anti-plasmodial potential A. from distinct locations within aiming to define optimal chemical composition terms activity....
Saturn has a sufficiently strong dipole magnetic field to trap high-energy charged particles and form radiation belts, which have been observed outside its rings. Whether stable belts exist near the planet inward of rings was previously unknown. The Cassini spacecraft's Magnetosphere Imaging Instrument obtained measurements belt that lies just above Saturn's dense atmosphere is decoupled from rest magnetosphere by planet's A- C-rings. extends across D-ring comprises protons produced through...
Abstract. The main auroral emission at Jupiter generally appears as a quasi-closed curtain centered around the magnetic pole. This feature, which accounts for approximately half of total power emitted by aurorae in ultraviolet range, is related to corotation enforcement currents middle magnetosphere. Early models these assumed axisymmetry, but significant local time variability obvious on any image Jovian aurorae. Here we use far-UV images from Hubble Space Telescope further characterize...
Abstract Jupiter has the most complex and energetic radiation belts in our Solar System one of challenging space environments to measure characterize in-depth. Their hazardous environment is also a reason why so many spacecraft avoid flying directly through their intense regions, thus explaining how Jupiter’s have kept secrets well hidden, despite having been studied for decades. In this paper we argue these are worth unveiling. vast magnetosphere that encloses them constitute an...
Abstract Recently, rotationally driven magnetic reconnection was first discovered in Saturn’s dayside magnetosphere. This newly confirmed process could potentially drive bursty phenomena at Saturn, i.e., pulsating energetic particles and auroral emissions. Using Cassini ’s measurements of fields charged particles, we investigate particle acceleration features during three events observed magnetodisk. The results suggest that the plays a key role producing electrons (up to 100 keV) ions...
Abstract Planetary magnetospheres receive plasma and energy from the Sun or moons of planets consequently stretch magnetic field lines. The process may last for varied timescales at different planets. From time to time, is rapidly released in magnetosphere subsequently precipitated into ionosphere upper atmosphere. Usually, this dissipation associated with dipolarization magnetosphere.This accompanied by acceleration field‐aligned current formation, auroral emissions are often significantly...
Abstract The main auroral emission at Jupiter results from the ionosphere‐magnetosphere coupling current system associated with corotation breakdown of iogenic plasma in sheet. morphology and brightness are generally suggested to be stable during time intervals order an hour. Here we reveal a transient small‐scale structure that is characterized by localized enhancement close noon local time. evolution this investigated both hemispheres on basis far UV images obtained Hubble Space Telescope...
Abstract The magnetospheric cusp is a region connecting the interplanetary environment to ionosphere and enabling solar wind particles reach ionosphere. We report detection of several isolated high‐latitude auroral emissions with Ultraviolet Imaging Spectrograph Cassini spacecraft. suggest that these spots, located in dawn‐to‐noon sector poleward main emission, are ionospheric signatures cusp, agreement some previous observations Hubble Space Telescope. signature has been associated lobe...
Abstract We surveyed energetic charged particle measurements by Cassini between 2016 and the end of mission in order to identify transients solar particles galactic cosmic rays. Such offer hints about state heliosphere valuable context for interpreting space weather phenomena Saturn's magnetosphere. The period studied includes mission's Ring‐Grazing Proximal orbits, which due their week‐long periods are ideal capturing short timescale dynamics planet's magnetosphere, including periodicities....
Abstract. The aurorae at Jupiter are made up of many different features associated with a variety generation mechanisms. main auroral emission, also known as the oval, is most prominent them it accounts for approximately half total power emitted by in ultraviolet range. energy precipitating electrons crucial parameter to characterize processes play which give rise these emissions, and altitude emissions directly depends on this energy. Here we make use far-UV (FUV) images acquired Advanced...
Abstract On 15 September 2017 the Cassini spacecraft plunged into Saturn's atmosphere after 13 years of successful exploration Saturnian system. The day before, Ultraviolet Imaging Spectrograph (UVIS) on board observed northern aurora for about 14 hr. During these observations, several auroral structures appeared, providing clues processes simultaneously occurring in magnetosphere. dawn enhancement together with magnetic field and plasma wave data suggest that an intense flux closure process...
Abstract Although auroral emissions at giant planets have been observed for decades, the physical mechanisms of aurorae remain unclear. One key reason is lack simultaneous measurements in magnetosphere while remote sensing aurora. We report a dynamic event identified with Cassini Ultraviolet Imaging Spectrograph (UVIS) Saturn on 13 July 2008 coordinated magnetic field and plasma magnetosphere. The intensification was transient, only lasting ∼30 min. are perturbed during period. suggest that...
Abstract During the Grand Finale Phase of Cassini , Ultraviolet Imaging Spectrograph on board spacecraft detected repeated detached small-scale auroral structures. We describe these structures as beads, a term introduced in terrestrial aurora. Those DOY 232 2017 are observed to extend over large range local times, i.e., from 20 LT 11 through midnight. suggest that beads related plasma instabilities magnetosphere, which often known generate wavy precipitations. Energetic neutral atom...
Abstract Jupiter's powerful auroral emission is usually divided into the polar, main, and equatorward components. The driver of main aurora a central question for community. Previous investigations reveal many distinct substructures on oval, which are indicators fundamentally different magnetospheric processes. Understanding these could provide key constraints uncovering emission. In this study, we show evolution double‐auroral arc dawnside from observations by Hubble Space Telescope (HST)....
<p>Jupiter has the most energetic and complex radiation belts in our solar system. Their hazardous environment is reason why so many spacecraft avoid rather than investigate them, explains how they have kept of their secrets well hidden, despite having been studied for decades. We believe that these are worth unveiling, as Jupiter’s vast magnetosphere encloses them constitute an unprecedented physical laboratory, suitable both interdisciplinary novel scientific...
Abstract The main ultraviolet auroral emission at Saturn consists of multiple structures forming a discontinuous ring around the poles, occasionally organized in global spiral. We present continuous observation an spiral rotating ∼ 85% rigid corotation during several hours. Simultaneously, energetic neutral atom (ENA) emissions revealed hot magnetospheric plasma population located same local time sector as ends Following theory, we propose that pressure gradients induced by energized...