Search Publications
Habitable periglacial landscapes in martian mid-latitudes
Hauber, E.; Ulrich, M.; Schirrmeister, L. +2 more
Subsurface permafrost environments on Mars are considered to be zones where extant life could have survived. For the identification of possible habitats it is important to understand periglacial landscape evolution and related subsurface and environmental conditions. Many landforms that are interpreted to be related to ground ice are located in th…
Quantification of middle and lower cloud variability and mesoscale dynamics from Venus Express/VIRTIS observations at 1.74 µm
Baines, Kevin H.; Grinspoon, David H.; Momary, Thomas W. +1 more
We present an analysis of VIRTIS-M-IR observations of 1.74 µm emission from the nightside of Venus. The 1.74 µm window in the near infrared spectrum of Venus is an ideal proxy for investigating the evolution of middle and lower cloud deck opacity of Venus because it exhibits good signal to noise due to its brightness, good contrast bet…
Cloud structure of Saturn's 2010 storm from ground-based visual imaging
Sánchez-Lavega, A.; Pérez-Hoyos, S.; Colas, F. +5 more
We present a study of the vertical cloud structure for the initial stage of the Great White Spot (GWS), a giant storm that developed in Saturn in December 2010, using ground-based visual images. We focus in the characterization of the undisturbed atmosphere preceding the storm and the disturbed region in the wake of the GWS. The observations were …
Structural asymmetry in martian impact craters as an indicator for an impact trajectory
Kenkmann, T.; Wulf, G.; Poelchau, M. H.
Impact crater formation is a highly dynamic and complex geological phenomenon. Methods of structural geology are capable of giving insights into deformation processes that occur during cratering. While most deformation observed in craters exhibits a generally radial symmetry, recent discoveries of non-radial structural elements in the central upli…
Late-stage impacts and the orbital and thermal evolution of Tethys
Zhang, Ke; Nimmo, Francis
An inferred ancient episode of heating and deformation on Tethys has been attributed to its passage through a 3:2 resonance with Dione (Chen, E.M.A., Nimmo, F. [2008]. Geophys. Res. Lett. 35, 19203). The satellites encounter, and are trapped into, the e-Dione resonance before reaching the e-Tethys resonance, limiting the degree to which Tethys is …
Production of N2 Vegard-Kaplan and other triplet band emissions in the dayglow of Titan
Bhardwaj, Anil; Jain, Sonal Kumar
Recently the Cassini Ultraviolet Imaging Spectrograph (UVIS) has revealed the presence of N2 Vegard-Kaplan (VK) band A3Σu+-X1Σg+ emissions in Titan's dayglow limb observation. We present model calculations for the production of various N2 triplet states (viz., A3Σu+,B3Πg,…
Mid-infrared spectra of differentiated meteorites (achondrites): Comparison with astronomical observations of dust in protoplanetary and debris disks
Koike, Chiyoe; Mason, Andrew; Morlok, Andreas +4 more
Mid-infrared (5-25 µm) transmission/absorption spectra of differentiated meteorites (achondrites) were measured to permit comparison with astronomical observations of dust in different stages of evolution of young stellar objects. In contrast to primitive chondrites, achondrites underwent heavy metamorphism and/or extensive melting and repre…
Spectral analysis and geological mapping of the Daedalia Planum lava field (Mars) using OMEGA data
Massironi, M.; Giacomini, L.; Carli, C. +1 more
The great variety of morphologies observed in the Daedalia Planum lava flows (Mars) encouraged a detailed study of their spectral characteristics, in order to obtain information about lava composition and detect possible differences in the spectra of the flows. The OMEGA spectral data collected from the lava field appear rather similar, with absor…
Regolith grain sizes of Saturn’s rings inferred from Cassini-CIRS far-infrared spectra
Spilker, Linda; Morishima, Ryuji; Edgington, Scott G.
We analyze far-infrared (10-650 cm-1) emissivity spectra of Saturn’s main rings obtained by the Cassini Composite Infrared Spectrometer (CIRS). In modeling of the spectra, the single scattering albedos of regolith grains are calculated using the Mie theory, diffraction is removed with the delta-Eddington approximation, and the hemispher…
Compositional analysis of Hyperion with the Cassini Visual and Infrared Mapping Spectrometer
Clark, Roger N.; Cruikshank, Dale P.; Brad Dalton, J.
Compositional mapping of the surface of Hyperion using Cassini Visual and Infrared Mapping Spectrometer (VIMS) observations reveals a heterogeneous surface dominated by water ice accompanied by additional materials. Carbon dioxide, as evidenced by a prominent absorption band centered at 4.26 µm, is distributed over most of the surface, inclu…