Search Publications
Bimodal aerosol distribution in Venus' upper haze from joint SPICAV-UV and -IR observations on Venus Express
Montmessin, F.; Fedorova, A.; Korablev, O. +3 more
Spectroscopic solar occultation measurements by the Spectroscopy for Investigation of Characteristics of the Atmosphere of Venus/Solar Occultation at Infrared instrument (SPICAV/SOIR) onboard the Venus Express orbiter gave new data about upper haze aerosol properties, its vertical distribution and spatial and temporal variations. Early study with …
Automatic crater shape retrieval using unsupervised and semi-supervised systems
Tewari, Atal; Jain, Vikrant; Khanna, Nitin
Impact craters are depressions formed due to impacts on the surface of planetary bodies. Recent deep learning-based crater detection methods assume craters as circular-shaped without much attention to extracting craters' shape and morphology. Craters' shape information (i.e., instance segmentation map for craters) can be helpful for many advanced …
Spectro-photometry of Phobos simulants: I. Detectability of hydrated minerals and organic bands
Hasselmann, Pedro H.; Poggiali, Giovanni; Fornasier, Sonia +12 more
Previous Mars Reconnaissance Orbiter and Mars Express observations of Phobos and Deimos, the moons of Mars, have improved our understanding of these small bodies. However, their formation and composition remain poorly constrained. Physical and spectral properties suggest that Phobos may be a weakly thermal-altered captured asteroid but the dynamic…
Ultraviolet spectrum reveals the presence of ozone on Jupiter's moon Callisto
Janardhan, P.; Bhardwaj, Anil; Ramachandran, R. +11 more
Sulphur dioxide (SO2) is known to be present on Callisto. In this paper, we studied the chemical evolution of SO2 astrochemical ice induced by irradiation using 9 eV (137.7 nm) vacuum ultraviolet light produced from the high-flux beamline of the storage ring at the National Synchrotron Radiation Research Centre in Taiwan. Ult…
Particle sizes in Saturn's rings from UVIS stellar occultations 2. Outlier Populations in the C ring and Cassini Division
Colwell, J. E.; Esposito, L. W.; Jerousek, R. G. +1 more
The Cassini Ultraviolet Imaging Spectrograph (UVIS) included a High-Speed Photometer (HSP), which observed hundreds of stellar occultations by Saturn's ring system across a range of viewing geometries (Colwell et al. 2010). The unocculted time series data from the HSP follow Poisson counting statistics, such that the second and third central momen…
Thermophysical arguments against basal melting in the south polar region of Mars
Ojha, Lujendra; Buffo, Jacob; Journaux, Baptiste
The south polar layered deposits (SPLD) on Mars is primarily composed of H2O ice, with smaller quantities of impurities such as CO2 ice and dust. The presence of these impurities can affect the thermal structure of the SPLD, increasing the basal temperature and potentially leading to basal melting. Recently, bright basal refl…
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…