Search Publications
Formation and disruption of aquifers in southwestern Chryse Planitia, Mars
Komatsu, Goro; Fairén, Alberto G.; Kargel, Jeffrey S. +7 more
We present geologic evidence suggesting that after the development of Mars' cryolithosphere, the formation of aquifers in southwestern Chryse Planitia and their subsequent disruption led to extensive regional resurfacing during the Late Hesperian, and perhaps even during the Amazonian. In our model, these aquifers formed preferentially along thrus…
The three-dimensional structure of Saturn's equatorial jet at cloud level
Hueso, R.; Sánchez-Lavega, A.; Pérez-Hoyos, S.
The three-dimensional structure of Saturn's intense equatorial jet from latitudes 8° N to 20° S is revealed from detailed measurements of the motions and spectral reflectivity of clouds at visible wavelengths on high resolution images obtained by the Cassini Imaging Science Subsystem (ISS) in 2004 and early 2005. Cloud speeds at two altitude level…
Stagnant lid convection in the mid-sized icy satellites of Saturn
Spohn, Tilman; Multhaup, Kai
Thermal history models for the mid-sized saturnian satellites Mimas, Tethys, Dione, Iapetus, and Rhea have been calculated assuming stagnant lid convection in undifferentiated satellites and varying parameter values over broad ranges. Of all five satellites under consideration, only Dione, Rhea and Iapetus do show significant internal activities r…
Properties of the dust cloud caused by the Deep Impact experiment
Jorda, L.; Lara, L. M.; Lamy, P. +7 more
We present an analysis of the observations of the Deep Impact event performed by the OSIRIS narrow angle camera aboard the Rosetta spacecraft over two weeks, in an effort to characterize the cometary dust grains ejected from the nucleus of Comet 9P/Tempel 1. We adopt a Monte Carlo approach to generate calibrated synthetic images, and a linear comb…
Interplanetary dust detected by the Cassini CDA Chemical Analyser
Postberg, Frank; Altobelli, Nicolas; Grün, Eberhard +7 more
During its cruise phase, prior to encountering Jupiter, the Cosmic Dust Analyser (CDA) onboard the Cassini spacecraft returned time of flight mass spectra (TOF MS) of two interplanetary dust particles. Both particles were found to be iron-rich, with possible traces of hydrogen, carbon, nickel, chromium, manganese, titanium, vanadium and minor sili…
Crater clusters on Mars: Shedding light on martian ejecta launch conditions
Richardson, Derek C.; Berman, Daniel C.; Popova, Olga P. +2 more
We have identified two classes of crater clusters on Mars. One class is "small clusters" (crater diameter D∼ tens m, spread over few hundred m), fitting our earlier calculations for the breakup of weak stone meteoroids in the martian atmosphere [Popova, O.P., Nemtchinov, I.V., Hartmann, W.K., 2003. Meteorit. Planet. Sci. 38, 905-925]. The second c…
Cassini CIRS update on stratospheric ices at Titan's winter pole
Achterberg, Richard K.; Smith, Michael D.; Samuelson, Robert E. +1 more
A strong, broad spectral emission feature at 85° N latitude centered at 221 cm -1 remains unidentified after candidate ices of H 2O and pure crystalline CH 3CH 2CN are unambiguously ruled out. A much shallower weak emission feature starts at 160 cm -1 and blends into the strong feature at ∼190…
The meridional phosphine distribution in Saturn's upper troposphere from Cassini/CIRS observations
Fletcher, L. N.; Irwin, P. G. J.; Teanby, N. A. +7 more
The Cassini Composite Infrared Spectrometer (CIRS) has been used to derive the vertical and meridional variation of temperature and phosphine (PH 3) abundance in Saturn's upper troposphere. PH 3 has a significant effect on the measured radiances in the thermal infrared and between May 2004 and September 2005 CIRS recorded tho…
Hubble Space Telescope observations of Comet 9P/Tempel 1 during the Deep Impact encounter
Weaver, Harold A.; Feldman, Paul D.; A'Hearn, Michael F. +4 more
We report on the Hubble Space Telescope program to observe periodic Comet 9P/Tempel 1 in conjunction with NASA's Deep Impact Mission. Our objectives were to study the generation and evolution of the coma resulting from the impact and to obtain wide-band images of the visual outburst generated by the impact. Two observing campaigns utilizing a tota…
Saturn's auroral/polar H +3 infrared emission . I. General morphology and ion velocity structure
Melin, Henrik; Miller, Steve; Stallard, Tom +3 more
We present an analysis of an extensive dataset of observations of the auroral/polar regions of Saturn, carried out in 2004 and 2005 using the high-resolution facility spectrometer CSHELL on the NASA Infrared Telescope Facility (IRTF) on Mauna Kea, Hawaii. The paper outlines the morphology of emission in the H +3νQ(1,0) line a…