Search Publications
Near-mid infrared spectroscopy of carbonaceous chondrites: Insights into spectral variation due to aqueous alteration and thermal metamorphism in asteroids
Zhao, Haibin; Cloutis, Edward A.; Yu, Jinfei +2 more
Carbonaceous chondrites (CCs) are windows into the early Solar System and the histories of their parent bodies. Their infrared spectral signatures are powerful proxies for deciphering their composition and evolution history, but still present formidable challenges in relation to determining the degree of secondary processing such as aqueous altera…
Effects of surface and subsurface water/ice on spatial distributions of impact crater ejecta on Mars
Wünnemann, Kai; Thomas, Nicolas; Sokołowska, Aleksandra
Ejecta blankets around craters on a km-scale show stark differences in the ejecta mobility (maximal extent of ejecta divided by the crater radius) with latitude and types of plains on Mars, which has been known for a long time (Barlow and Pollak, 2002; Li et al., 2015) but is not well-understood. Our main goal is to explore the idea that the subsu…
New gravity field of comet 67P/C-G based on Rosetta's Doppler and optical data
Marty, Jean-Charles; Jorda, Laurent; Le Maistre, Sebastien +3 more
The gravity field of a celestial body gives valuable insights into its fundamental properties such as its density and internal structure. The Doppler data collected by the Radio-Science Investigation (RSI) experiment of the Rosetta mission were previously used to determine the gravity field of comet 67P/Churyumov–Gerasimenko up to degree 2 (Pätzol…
Exploring sensitivity: Unveiling the impact of input parameters on Venus ionosphere V2 layer characteristics
Choudhary, R. K.; Ambili, K. M.; Tripathi, Keshav R.
This study investigates the impact of model input parameters on the characteristic features of the dayside V2 layer in the Venus ionosphere using an in-house developed one-dimensional photochemical model (1D-PCM) and observations from Venus Express radio science experiments (VeRa). 1D-PCM is simulated for different combinations of neutr…
Modeling the plasma composition of 67P/C-G at different heliocentric distances
Ahmed, Sana; Soni, Vikas
The Rosetta spacecraft accompanied the comet 67P/C-G for nearly 2 years, collecting valuable data on the neutral and ion composition of the coma. The Rosetta Plasma Consortium (RPC) provided continuous measurements of the in situ plasma density while ROSINA-COPS monitored the neutral composition. In this work, we aim to estimate the composition of…
H2CO, O3, NH3, HCN, N2O, NO2, NO, and HO2 upper limits of detection in the Venus lower-mesosphere using SOIR on board Venus Express
Aoki, S.; Vandaele, A. C.; Trompet, L. +6 more
We report on mean upper limit number densities and volume concentrations of H2CO, O3, NH3, HCN, N2O, NO2, NO, and HO2 at the Venus terminator above the cloud layer, computed from the SOIR/Venus Express transmittances measured during hundreds of solar occultations. An unsuccessful at…
The puzzling north polar region of Uranus: Continued zero-shear winds and increasing brightness from 2015 through 2022 according to 7 years of Keck AO imaging
de Pater, Imke; Sromovsky, Lawrence A.; Fry, Patrick M. +1 more
There may be a permanent north–south asymmetry in the zonal wind profile of Uranus. According to high signal-to-noise near-IR observations with the Keck telescope NIRC2 camera, through 2014 the winds north of 60∘N had a constant (zero shear) longitudinal drift rate of 4.1∘/h westward (Sromovsky et al., 2015). Yet the south polar winds in 1986 had …
Observation of the Southern Polar cap during MY34-36 with ExoMars-TGO NOMAD LNO
Vandaele, A. C.; Daerden, F.; Thomas, I. R. +12 more
Mainly designed to study minor atmospheric species in the Martian atmosphere, the Nadir and Occultation for MArs Discovery (NOMAD) instrument suite onboard the 2016 ExoMars Trace Gas Orbiter (TGO) can also be exploited for surface ice detection. In this work, we investigate the nadir observations of the NOMAD infrared channel from the Martian Year…
Three-dimensional Venusian ionosphere model
Chaufray, Jean-Yves; Lefèvre, Franck; Lebonnois, Sébastien +3 more
To study the Venusian ionosphere, a 3D ionospheric model is included in the Venus Planetary Climate Model (Venus PCM), which we present here with a number of recent extensions and improvements. Our ionospheric model of Venus consists of 15 charged species (electron and 14 ions), 13 photo-ionization for 8 species, an ion-neutral chemistry (61 react…
Comprehensive observations and geostatistics of slope streaks within the Olympus Mons aureole
Stillman, D. E.; Primm, K. M.; Hoover, R. H. +3 more
Slope streaks (SS) are enigmatic linear features characterized by relatively low-albedo features that appear and fade on high-albedo slopes on Mars. Despite numerous hypotheses proposed to explain their formation, the primary mechanism behind SS remains elusive. Here, we examine 702 SS features using 32 multitemporal Context Imager (CTX) images an…