Search Publications
The Temporal Brightening of Uranus' Northern Polar Hood From HST/WFC3 and HST/STIS Observations
Wong, Michael H.; Fletcher, Leigh N.; Irwin, Patrick G. J. +8 more
Hubble Space Telescope Wide-Field Camera 3 (HST/WFC3) observations spanning 2015 to 2021 confirm a brightening of Uranus' north polar hood feature with time. The vertical aerosol model of Irwin et al. (2023, https://doi.org/10.1038/s41550-023-02047-0) (IRW23), consisting of a deep haze layer…
Evidence of Non-Thermal Hydrogen in the Exosphere of Mars Resulting in Enhanced Water Loss
Bertaux, J. L.; Clarke, J. T.; Halekas, J. +9 more
Atomic H is a direct tracer of water loss at Mars. The recent discovery of annual enhancements in its escape rate near perihelion, in excess of the previously established theory, indicates that Mars has lost substantial amounts of water to space. However, these loss rates are often estimated assuming thermal properties for the exospheric H atoms a…
Thermal Tides on Mars Before and During the 2018 Global Dust Event as Observed by TIRVIM-ACS Onboard ExoMars Trace Gas Orbiter
Grigoriev, A.; Forget, F.; Montmessin, F. +8 more
Migrating tides dominate the tropical climate on Mars and are known to reach high amplitudes during global dust events (GDE). In this study, we characterize the amplitude, phase and vertical wavelength of the diurnal and semidiurnal migrating tides in Mars' lower atmosphere (up to 50 km) by exploiting temperature vertical profiles retrieved from T…
Long-Lived and Continual Volcanic Eruptions, Tectonic Activity, Pit Chains Formation, and Boulder Avalanches in Northern Tharsis Region: Implications for Late Amazonian Geodynamics and Seismo-Tectonic Processes on Mars
Kumar, P. Senthil; Krishnan, Vivek
Tharsis is the largest volcanic province on Mars. It consists of a few large shield volcanoes, one of which is Alba Mons (AM), located in northern Tharsis, with the Ceraunius Fossae (CF) graben system to the south of it. Previous workers argued in favor of episodic building of Tharsis volcanoes. In contrast, we show that volcanism in the AM and CF…
Venusian Ionosphere During Deep Solar Minima: Some New Insights Using Akatsuki Radio Science Experiment
Choudhary, R. K.; Imamura, T.; Ambili, K. M. +1 more
The characteristic features of different layers in the Venus ionosphere during the deep solar minimum of the solar cycle 24 have been studied using a radio science experiment onboard the Akatsuki spacecraft. Radio signals from the spacecraft were tracked at the Indian deep space network, Bangalore; Usuda Deep Space Center, Japan; and DLR Ground st…
Quantifying Morphological Changes and Sediment Transport Pathways on Comet 67P/Churyumov-Gerasimenko
Vincent, J. -B.; Hayes, A. G.; Birch, S. P. D. +3 more
Comets are active geological worlds with primitive surfaces that have been shaped to varying degrees by sublimation-driven sediment transport and mass wasting processes. Rosetta's rendezvous with comet 67P/Churyumov-Gerasimenko (67P) in 2014 provided data with the necessary spatial and temporal resolutions to observe many evolutionary processes on…
Can Clay Mimic the High Reflectivity of Briny Water Below the Martian SPLD?
Caprarelli, Graziella; Pettinelli, Elena; Cosciotti, Barbara +6 more
It has recently been suggested that clay minerals, which are widespread on the Martian surface, could be the possible source of the basal bright reflections detected by MARSIS at Ultimi Scopuli, instead of briny water. This hypothesis is based on dielectric measurements on a wet Ca-Montorillonite (STx-1b) sample conducted at 230 K, which reported …
Temporal Variations in Vertical Cloud Structure of Jupiter's Great Red Spot, Its Surroundings and Oval BA From HST/WFC3 Imaging
Irwin, Patrick G. J.; Sánchez-Lavega, Agustín.; Anguiano-Arteaga, Asier +2 more
In this study, we present the evolution of the properties and vertical distribution of the hazes in Jupiter's Great Red Spot (GRS), its surroundings and Oval BA from 2015 to 2021. To retrieve the main atmospheric parameters, we model the spectral reflectivity of a number of dynamically and/or spectrally interesting regions with a radiative transfe…
Hydrothermal Alteration of Ultramafic Rocks in Ladon Basin, Mars—Insights From CaSSIS, HiRISE, CRISM, and CTX
Tornabene, Livio L.; Hauber, Ernst; Mège, Daniel +21 more
The evolution of the Ladon basin has been marked by intense geological activity and the discharge of huge volumes of water from the Martian highlands to the lowlands in the late Noachian and Hesperian. We explore the potential of the ExoMars Trace Gas Orbiter/Color and Stereo Surface Imaging System color image data set for geological interpretatio…
The Ultraviolet Martian Dayglow Observed With NOMAD/UVIS on ExoMars Trace Gas Orbiter
Vandaele, A. C.; Thomas, I. R.; Ristic, B. +9 more
The Trace Gas Orbiter has been orbiting Mars since 2016 with the Nadir and Occultation for MArs Discovery (NOMAD) UltraViolet and Visible Spectrometer (UVIS) instrument on board. Focusing on limb observations recorded in the ultraviolet (UV) part of the NOMAD/UVIS spectra, we describe here the CO Cameron bands, CO2+ UV double…