A5002279904- Astro and Planetary Science
- Planetary Science and Exploration
- Isotope Analysis in Ecology
- Astrophysics and Star Formation Studies
- Stellar, planetary, and galactic studies
- Atmospheric Ozone and Climate
- Spacecraft and Cryogenic Technologies
- Space Exploration and Technology
- Solar and Space Plasma Dynamics
- Gamma-ray bursts and supernovae
- Space exploration and regulation
- Astronomy and Astrophysical Research
- Spacecraft Design and Technology
- History and Developments in Astronomy
- Space Science and Extraterrestrial Life
- Geology and Paleoclimatology Research
- Spaceflight effects on biology
- Laser-induced spectroscopy and plasma
- Arctic and Antarctic ice dynamics
- Paleontology and Stratigraphy of Fossils
- Atmospheric and Environmental Gas Dynamics
- Science Education and Perceptions
- Astronomical Observations and Instrumentation
- Methane Hydrates and Related Phenomena
- Pulsars and Gravitational Waves Research
Southwest Research Institute
2017-2024
The University of Texas at San Antonio
2021-2024
University of Duisburg-Essen
2022-2024
University of Central Florida
2014-2021
TU Dresden
2021
Imperial Valley College
2021
Georgia Institute of Technology
2021
Planetary Science Institute
2021
Jet Propulsion Laboratory
2021
Auburn University
2021
Abstract Recent visible-wavelength observations of Europa’s surface obtained with the Hubble Space Telescope (HST) revealed presence an absorption feature near 450 nm that appears spatially correlated leading-hemisphere chaos terrain. This was interpreted to reflect irradiated sodium chloride ultimately sourced from interior. Here, we use ultraviolet spectra also collected HST detect additional previously unseen 230 nm, which correlates and same We find new is well matched by at Europa-like...
Abstract Jupiter’s icy moon, Europa, harbors a subsurface liquid water ocean; the prospect of this ocean being habitable motivates further exploration moon with upcoming NASA Europa Clipper mission. Key among mission goals is comprehensive assessment moon’s composition, which essential for assessing Europa’s habitability. Through powerful remote sensing and in situ investigations, will explore composition surface subsurface, its tenuous atmosphere, local space environment surrounding moon....
Abstract We used the FORCAST instrument on SOFIA to obtain mid-infrared spectra (4.9–13.7 μ m) of four S-type asteroids: (7) Iris, (11) Parthenope, (18) Melpomene, and (20) Massalia. Three these silicate-rich asteroids (Iris, Massalia) were observed have 3 m features indicative hydration by McAdam et al. report a detection 6 feature that is unambiguously attributed molecular water two asteroids, Iris Massalia, with peak heights 4.532% ± 0.011% 4.476% 0.012%, respectively. estimate abundance...
We report radar observations (2380-MHz, 13-cm) by the Arecibo Observatory and optical light curves observed from eight different observatories collected at Ondřejov of triple near-Earth asteroid system (153591) 2001 SN263. The were obtained over course ten nights spanning February 12–26, 2008 curve made throughout January 12 - March 31, 2008. Both data sets include during object's close approach 0.06558 AU on 20th, delay-Doppler images revealed to be comprised three components, making it...
Abstract During 2023 September the Alice ultraviolet spectrograph on New Horizons (NH) spacecraft was used to map diffuse Lyα emission over most of sky, at a range ∼56.9 au from Sun. At that distance, models predict interplanetary medium Ly α emissions result comparable amounts resonant backscattering solar line by interstellar hydrogen atoms (H i ) passing through system, in addition an approximately isotropic background ∼50 ± 20 R local (LISM). The NH observations show no strong...
ABSTRACT We report far-ultraviolet observations of Europa in transit Jupiter obtained with the Space Telescope Imaging Spectrograph Hubble on six occasions between 2014 December and 2015 March. Absorption Jupiter’s bright hydrogen Ly α dayglow is detected a region several moon radii above limb all observations. The observed extended absorption provides first detection an atomic corona around Europa. Molecular constituents Europa’s global sputtered atmosphere are shown to be optically thin ....
Abstract Ultraviolet spectroscopy is a powerful method to study planetary surface composition through reflectance measurements, atmospheric stellar/solar occultations, transits of other bodies, and direct imaging airglow auroral emissions. The next generation ultraviolet spectrographs (UVS) on board ESA’s Jupiter Icy Moons Explorer NASA’s Europa Clipper missions will perform such measurements its moons in the early 2030s. This work presents compilation detailed UV stellar catalog, named...
ABSTRACT Particles regularly tribocharge in collisions. Here, we study how long charges can persist on such particles the environment of a protoplanetary disc. We set up three complementary experiments to quantify discharge time-scales. first directly measure time dependency charge triboelectrically charged objects. For this aspect, performed two long-time under different environmental conditions. find that persists tribocharged bodies time-scales between minutes and years. Discharge might...
Abstract Our understanding of solar system evolution is closely tied to interpretations asteroid composition, particularly the M-class asteroids. These asteroids were initially thought be exposed cores differentiated planetesimals, a hypothesis based on their spectral similarity iron meteorites. However, recent astronomical observations have revealed hydration surface through detection 3 μ m absorption features associated with OH and potentially H 2 O. We present evidence due mainly (16)...
Abstract We present spatially resolved reflectance spectra of Europa’s surface in the wavelength range 210–315 nm obtained by Hubble Space Telescope Imaging Spectrograph 2018 and 2019. These data provide first high-quality, near-global spectral observations Europa from 210 to 240 nm. They show that leading, trailing, anti-Jovian, sub-Jovian hemispheres is ∼5% near nm, with varying slopes across mid-UV. This low albedo, even on more “pristine” leading hemisphere, indicates a lack signature...
We report results from far-ultraviolet observations by the Hubble Space Telescope of Jupiter's largest moon Ganymede transiting across planet's dayside hemisphere. {Within} a targeted campaign on 9 September 2021 two exposures were taken during one transit passage to probe for attenuation hydrogen Lyman-$\alpha$ dayglow above limb. The background is slightly attenuated over an extended region around Ganymede, with stronger in second exposure when was near center. In first closer limb,...
Planetesimals or smaller bodies in protoplanetary disks are often considered to form as pebble piles current planet formation models. They supposed be large but loose, weakly bound clusters of more robust dust aggregates. This makes them easy prey for destructive processes. In microgravity experiments, we apply strong electric fields on slightly conductive We find that this generates enough tensile stress the fragile sequentially rip off aggregates from cluster. These experiments imply can...
Abstract We present reflectance spectra of Ganymede's leading and trailing hemispheres in the wavelength range 138–215 nm, obtained by Hubble Space Telescope Cosmic Origins Spectrograph (HST/COS) 2014. The most notable feature both is absence a sharp water absorption edge at ~165 seen laboratory measurements ice reflectivity previous observations Saturn's icy moons rings. Rather than displaying change edge, gradually increases with λ > 165 nm. show that observed shape UV inconsistent...
Abstract The Neptune Odyssey mission concept is a Flagship-class orbiter and atmospheric probe to the Neptune–Triton system. This bold of exploration would orbit an ice-giant planet study planet, its rings, small satellites, space environment, planet-sized moon Triton. Triton captured dwarf from Kuiper Belt, twin Pluto, likely ocean world. addresses system-level science, with equal priorities placed on Neptune, moons, Between Uranus latter unique in providing simultaneous access both ice...
Abstract In December 2001, the Space Telescope Imaging Spectrograph of Hubble obtained far‐ultraviolet spectral images Jupiter's moon Callisto. The leading and trailing hemispheres were observed in range 1190 Å to 1720 when was at eastern western elongations, respectively. We analyzed hydrogen Lyman α (1216 Å) signal two observations found that faint atmospheric emissions extending up several radii away are present addition solar flux reflected off surface. show detected consistent with an...
Abstract We present an analysis of Europa's far‐UV spectral albedo using observations during the 1999–2015 time period made by Space Telescope Imaging Spectrograph on Hubble Telescope. Disk‐integrated show that spectrum in ~130 to 170‐nm range is relatively flat or slightly blue (increasing with decreasing wavelength) for studied hemispheres: leading, trailing, and anti‐Jovian hemispheres. At Lyman‐α (121.6 nm), trailing hemisphere continues trend, but it reddens leading hemisphere. Also at...
Abstract The Main Belt Asteroid (16) Psyche is the target object of NASA Discovery Mission Psyche. We observed asteroid at ultraviolet (UV) wavelengths (170–310 nm) using Space Telescope Imaging Spectrograph on Hubble during two separate observations. report that spectrum very red in UV, with a blue upturn shortward ∼200 nm. find an absorption feature 250 nm and weaker 275 may be attributed to metal-oxide charge transfer band. red-sloped, relatively featureless best matched reflectance pure...
Abstract In situ plasma measurements as well remote mapping of energetic neutral atoms around Jupiter provide indirect evidence that an enhancement gas is present near the orbit moon Europa. Simulations suggest such a torus can be sustained by escape from Europa’s atmosphere and consists primarily molecular hydrogen, but has not yet been measured directly through emissions or in situ. Here we observations Cosmic Origins Spectrograph (COS) Hubble Space Telescope (HST) 2020 to 2021, which...
Abstract Asteroid (16) Psyche is theorized to be an exposed iron core of a primordial asteroid and the target upcoming NASA mission. Recent observations identified presence rotational heterogeneity, fine-grained regolith, pyroxene, hydrated minerals on its surface. We obtained rotationally resolved mid-infrared (MIR) spectroscopy with Stratospheric Observatory for Infrared Astronomy explore compositional heterogeneity assess mineralogy. used thermophysical model estimate remove thermal flux...
Este estudo bibliográfico examinou a Aprendizagem Baseada em Problemas (ABP) como metodologia ativa no contexto do suporte educacional para estudantes com Transtorno Espectro Autista (TEA), focando suas estratégias e benefícios potencializar o processo de ensino-aprendizagem. A pesquisa analisou literatura atual sobre tema, investigando aplicação da ABP ensino alunos TEA, seus desafios possibilidades. Os achados sugerem que pode promover significativamente desenvolvimento habilidades...
Abstract We report physical and mutual orbit characteristics of near-Earth binary asteroid (163693) Atira. Using S -band (2380 MHz, 12.6 cm) radar observations from the Arecibo Observatory several epochs lightcurve 2003 to 2019 with SHAPE modeling software, we determine shape, size, rotational period, primary secondary components density component. confirm primary’s sidereal rotation period be 3.398521 ± 0.000003 hr, find a likely spin axis orientation ecliptic longitude latitude (187°,...
The Arecibo Observatory (AO) is a multidisciplinary research and education facility that recognized worldwide as leading in astronomy, planetary, atmospheric space sciences. AO's cornerstone instrument was the 305-m William E. Gordon telescope. On December 1, 2020, telescope collapsed irreparably damaged. In three weeks following collapse, scientific engineering staff AO users community initiated extensive discussions on future of observatory. overwhelming agreement there need to build an...