Search Publications
Multi-spectrum retrieval of Venus IR surface emissivity maps from VIRTIS/VEX nightside measurements at Themis Regio
Haus, Rainer; Kappel, David; Arnold, Gabriele
Surface emissivity maps in the infrared can contribute to explore Venus' geology. Nightside radiance spectra at Themis Regio acquired by the IR mapping channel of the Visible and InfraRed Thermal Imaging Spectrometer (VIRTIS-M-IR) aboard Venus EXpress (VEX) are used to derive emissivity data from the three accessible spectral surface windows at 1.…
Transport and electrodynamical coupling of nano-grains ejected from the Saturnian rings and their possible ionospheric signatures
Ip, W. -H.; Liu, C. -M.; Pan, K. -C.
Besides oxygen-bearing neutral gas and ions, the Saturnian rings could be a source of small dust particles of nano-meter size range. Electrostatic charging effect by photoemission and/or electron impact could lead to ejection of the nano-grains out of the ring plane by electromagnetic force. The orbital motion of low-velocity charged dust generate…
Radar scattering of linear dunes and mega-yardangs: Application to Titan
Radebaugh, Jani; Paillou, Philippe; Wall, Stephen +1 more
The Ku-band (13.8 GHz - 2.2 cm) RADAR instrument onboard the Cassini-Huygens spacecraft has revealed the richness of the surface of Titan, as numerous seas, lakes, rivers, cryo-volcanic flows and vast dune fields have been discovered. Linear dunes are a major geomorphological feature present on Titan, covering up to 17% of its surface, mainly in e…
Planetary period oscillations in Saturn's magnetosphere: Further comments on the relationship between post-equinox properties deduced from magnetic field and Saturn kilometric radiation measurements
Cowley, S. W. H.; Provan, G.
We discuss the planetary period oscillations (PPOs) observed by the Cassini spacecraft in Saturn's magnetosphere, in particular the relationship between the properties of the PPOs in the post-equinox interval as observed in magnetic field data by Andrews et al. (2012) and Provan et al. (2013, 2014) and in Saturn kilometric radiation (SKR) emission…
Surface ages of mid-size saturnian satellites
Di Sisto, Romina P.; Zanardi, Macarena
The observations of the surfaces of the mid-sized saturnian satellites made by Cassini-Huygens mission have shown a variety of features that allows study of the processes that took place and are taking place on those worlds. Research of the saturnian satellite surfaces has clear implications not only for Saturn's history and Saturn's surroundings,…
Impact ejecta-induced melting of surface ice deposits on Mars
Head, James W.; Weiss, David K.
Fluvial features present around impact craters on Mars can offer insight into the ancient martian climate and its relationship to the impact cratering process. The widespread spatial and temporal distribution of surface ice on Mars suggests that the interaction between impact cratering and surface ice could have been a relatively frequent occurren…
Variations in Titan's dune orientations as a result of orbital forcing
Tokano, Tetsuya; Lucas, Antoine; Newman, Claire E. +6 more
Wind-blown dunes are a record of the climatic history in Titan's equatorial region. Through modeling of the climatic conditions associated with Titan's historical orbital configurations (arising from apsidal precessions of Saturn's orbit), we present evidence that the orientations of the dunes are influenced by orbital forcing. Analysis of 3 Titan…
High precision comet trajectory estimates: The Mars flyby of C/2013 A1 (Siding Spring)
Micheli, M.; Farnocchia, D.; Delamere, W. A. +6 more
The Mars flyby of C/2013 A1 (Siding Spring) represented a unique opportunity for imaging a long-period comet and resolving its nucleus and rotation state. Because of the small encounter distance and the high relative velocity, the goal of successfully observing C/2013 A1 from the Mars orbiting spacecraft posed strict accuracy requirements on the c…
Disk-resolved photometry of Vesta and Lutetia and comparison with other asteroids
Longobardo, Andrea; Palomba, Ernesto; De Sanctis, Maria Cristina +7 more
Photometry of asteroids gives fundamental information about their spectral and physical properties. The aim of this work is two-fold: (1) to calculate phase functions of Vesta and Lutetia in the visible spectral range; and (2) to compare photometric properties of all the asteroids visited by space missions, as inferred from disk-resolved photometr…
Thermal properties of Rhea's poles: Evidence for a meter-deep unconsolidated subsurface layer
Spencer, J. R.; Howett, C. J. A.; Segura, M. +2 more
Cassini's Composite Infrared Spectrometer (CIRS) observed both of Rhea's polar regions during a close (2000 km) flyby on 9th March 2013 during orbit 183. Rhea's southern pole was again observed during a more distant (51,000 km) flyby on 10th February 2015 during orbit 212. The results show Rhea's southern winter pole is one of the coldest places d…