Search Publications
Solar wind plasma protrusion into the martian magnetosphere: ASPERA-3 observations
Coates, A. J.; Kallio, E.; Fedorov, A. +37 more
The ASPERA-3 experiment onboard the Mars Express spacecraft revealed, near the wake boundary of Mars, a spatially narrow, strip-like plasma structure composed of magnetosheath-like electrons and planetary ions. The peak electron energy often exceeds the peak energy at the bow shock that indicates a significant heating (acceleration) during the str…
Martian phase function: Modeling the visible to near-infrared surface photometric function using HST-WFPC2 data
Soderblom, Jason M.; Bell, James F.; Wolff, Michael J. +1 more
Images of Mars in the visible to near-infrared acquired from 1996 to 2005 using the Hubble Space Telescope WFPC2 have been used to model the martian surface photometric function at 502, 673, 953, and 1042 nm. These data range in spatial resolution from 12 to 70 km/pixel at the sub-Earth point, and in phase angle coverage from 0.34° to 40.5°. The W…
Physical properties of Titan's surface at the Huygens landing site from the Surface Science Package Acoustic Properties sensor (API-S)
Lorenz, R. D.; Hagermann, A.; Leese, M. R. +6 more
We present the results from the first sonar to be deployed outside of Earth, and the first active acoustic instrument on Titan, onboard the Huygens probe, and the implications of its data for the geomorphology and characteristics of the Huygens landing site. Signals were recorded from 90 m downwards until impact, with a maximum sensor footprint di…
ASPERA-3 on Mars Express
Barabash, Stas; Lundin, Rickard
Possible remnants of a frozen mud lake in southern Elysium, Mars
Smith, Michael D.; Markiewicz, Wojciech J.; Page, David +2 more
In this work we estimate the minimum persistence time of subsurface ice in water rich sediment layers remaining after sublimation of a martian lake. We simulate sublimation of ice from layers of different granulations and thicknesses. Presented results assume insolation and atmospheric conditions characteristic for the present day southern Elysium…
Evolution of depressions on Comet 67P/Churyumov Gerasimenko: Role of ice metamorphism
Kossacki, Konrad J.; Leliwa-Kopystyński, Jacek; Szutowicz, Slawomira
This work is intended to investigate the influence of temperature-dependent metamorphism of ice on the shape of small depressions in the surface of cometary nuclei. We are mainly interested in the role of initial cohesivity of a nucleus. For this purpose we simulate sublimation of ice from the facets of initially cylindrical depressions in ice of …
New upper limits for hydrogen halides on Saturn derived from Cassini-CIRS data
Fletcher, L. N.; Irwin, P. G. J.; Teanby, N. A. +2 more
Far infrared spectra (10-600 cm -1) from Cassini's Composite InfraRed Spectrometer (CIRS) were used to determine improved upper limits of hydrogen halides HF, HCl, HBr, and HI in Saturn's atmosphere. Three observations, comprising a total of 3088 spectra, gave 3 σ upper limits on HF, HCl, HBr, and HI volume mole fractions of 8.0×10, 6.7…
A tidal explanation for the Titan haze layers
Schubert, Gerald; Walterscheid, Richard L.
Though Titan is in synchronous rotation around Saturn, it experiences gravitational tides as a consequence of its eccentric orbit. It is proposed that the vertical transport of aerosols by these tides produces the haze layers in Titan's upper atmosphere. Analysis shows that the zonal winds in Titan's superrotating atmosphere have a profound influe…
HST BVI photometry of Triton and Proteus
Pascu, Dan; Rohde, James R.; Seidelmann, P. Kenneth +4 more
BVI photometry of Triton and Proteus was derived from HST images taken in 1997. The VEGAMAG photometric technique was used. Triton was found to be brighter by a few percent than observations of the 1970's and 1980's, as expected due to the increasingly greater exposure of the bright south polar region. The leading side was also found to be brighte…
Measurements of winds on Mars with Hubble Space Telescope images in 2003 opposition
Videen, G.; Kaydash, V. G.; Kreslavsky, M. A. +3 more
The winds of Mars at the water cloud level are measured by tracking cloud features in sequential high-resolution Hubble Space Telescope UV images for 5 days during the perihelion season in 2003. Global circulation model (GCM) predictions are in general agreement with the observations for the zonal wind component, but reveal significant differences…