Search Publications
What the ancient phyllosilicates at Mawrth Vallis can tell us about possible habitability on early Mars
Murchie, Scott L.; Bishop, Janice L.; Parente, Mario +5 more
Phyllosilicate deposits on Mars provide an opportunity to evaluate aqueous activity and the possibility that habitable environments may have existed during the Noachian period there. Analysis of hyperspectral visible/near-infrared (VNIR) Mars Reconnaissance Orbiter (MRO) Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) images has shown…
Revisiting cometary bow shock positions
Glassmeier, K. -H.; Richter, I.; Rubin, M. +2 more
The Rosetta spacecraft will arrive at comet 67P/Churyumov-Gerasimenko in 2014 and will escort the comet along its journey around the Sun. The predicted outgassing rate of the comet and the solar wind properties close to its perihelion at 1.24 AU lead to the expectation that a cometary bow shock will form during the escort phase. Since the forecast…
Negative ion densities in the ionosphere of Titan-Cassini RPWS/LP results
Wahlund, J. -E.; Edberg, N. J. T.; Ågren, K. +3 more
The Cassini spacecraft Radio and Plasma Wave Science (RPWS) Langmuir Probe (LP) provides in-situ measurements of Titan's ionosphere. We present here data from 47 deep flybys in the time period October 2004-July 2012 of charge densities of positive and negative ions as well as electrons. These densities have been mapped with respect to altitude and…
Auroral counterpart of magnetic field dipolarizations in Saturn's tail
Dougherty, Michele K.; Cowley, Stanley W. H.; Bunce, Emma J. +6 more
Following magnetic reconnection in a planetary magnetotail, newly closed field lines can be rapidly accelerated back towards the planet, becoming "dipolarized" in the process. At Saturn, dipolarizations are initially identified in magnetometer data by looking for a southward turning of the magnetic field, indicating the transition from a radially …
Can laboratory tholins mimic the chemistry producing Titan's aerosols? A review in light of ACP experimental results
Poch, O.; Szopa, C.; Coll, P. +7 more
The first results obtained by the ACP experiment onboard Huygens probe revealed that the main products obtained after thermolysis of Titan's collected aerosols, were ammonia (NH3) and hydrogen cyanide (HCN). Titan's aerosols, and their laboratory analogues named tholins, have been the subject of experimental or theoretical studies durin…
Mars impact ejecta in the regolith of Phobos: Bulk concentration and distribution
Head, James W.; Ramsley, Kenneth R.
The gravity of Mars and the observation of a thick Phobos regolith suggest that nearly all Phobos ejecta returns to Phobos and re-impacts on Phobos. Primary ejecta from Mars typically impacts Phobos at velocities of ~2-3 km/s and due to the low escape velocity from Phobos of ~4-10 m/s, ~95-99% of the secondary ejecta from Phobos is inserted into t…
Gypsum, opal, and fluvial channels within a trough of Noctis Labyrinthus, Mars: Implications for aqueous activity during the Late Hesperian to Amazonian
Weitz, Catherine M.; Grant, John A.; Bishop, Janice L.
We investigate in detail the morphology, mineralogy, and stratigraphy of light-toned deposits within one trough of Noctis Labyrinthus, centered at -6.8°N, 261.1°E. CRISM spectra taken from light-toned layered deposits in the northern portion of the trough exhibit absorptions around 1.41, 1.92 and 2.21 µm, consistent with mixtures of opal and…
Self-consistent retrieval of temperature profiles and cloud structure in the northern hemisphere of Venus using VIRTIS/VEX and PMV/VENERA-15 radiation measurements
Kappel, D.; Arnold, G.; Haus, R.
Improved radiative transfer simulation and multi-window retrieval procedures (MWR) are described that are applied to investigate thermal structure and cloud features in the nightside atmosphere of Venus over the northern hemisphere. Comparative analyses of spectroscopic data, which were recorded independently in different parts of the infrared spe…
Constraints on Titan's middle atmosphere ammonia abundance from Herschel/SPIRE sub-millimetre spectra
Hartogh, P.; Lellouch, E.; Irwin, P. G. J. +6 more
Sub-millimetre spectra measured with Herschel's SPIRE Fourier Transform Spectrometer were used to search for ammonia (NH3) in Titan's stratosphere. Observations were taken during 2010 and 2011, just after Titan's northern spring equinox, which occurred in mid-2009. In our analysis we used high spectral resolution data (0.074 cm-1
Evolution of the Io footprint brightness I: Far-UV observations
Saur, J.; Bonfond, B.; Clarke, J. T. +6 more
The Io footprint (IFP) is a set of auroral spots and an extended tail resulting from the strong interaction between Io and the Jovian magnetosphere. For the first time, we present measurements of the brightness and precipitated power for each individual spot, using the image database gathered from 1997 to 2009 with the Hubble Space Telescope in th…