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Cassini detection of Enceladus' cold water-group plume ionosphere
Coates, A. J.; Thomsen, M. F.; Wilson, R. J. +6 more
This study reports direct detection by the Cassini plasma spectrometer of freshly-produced water-group ions (O+, OH+, H2O+, H3O+) and heavier water dimer ions (HxO2)+ very close to Enceladus where the plasma begins to emerge from the plume. The data …
Amazonian-aged fluvial valley systems in a climatic microenvironment on Mars: Melting of ice deposits on the interior of Lyot Crater
Head, J. W.; Dickson, J. L.; Fassett, C. I.
Valley networks, regional drainage patterns suggesting liquid water stability at the surface, are confined to early in the history of Mars (the Noachian/Hesperian boundary and before), prior to a major climate transition to the hyperarid cold conditions of the Amazonian. Several later fluvial valley systems have been documented in specific Hesperi…
Detecting nanoparticles at radio frequencies: Jovian dust stream impacts on Cassini/RPWS
Gurnett, D. A.; Kaiser, M. L.; Meyer-Vernet, N. +1 more
We analyse wave observations by the Cassini/RPWS instrument performed during the Jovian fly-by, when the on-board dust analyser recorded dust streams which were interpreted as nanoparticles moving at about the solar wind speed. The observed wave pulses are produced by ionisation of dust grains impacting the spacecraft. Nanoparticles are detected b…
Source regions of banded chorus
Pickett, J. S.; Inan, U. S.; Bell, T. F. +1 more
ELF/VLF chorus emissions are very intense electromagnetic plasma waves that are naturally and spontaneously excited near the magnetic equatorial plane outside the plasmasphere during periods of magnetic disturbance. These emissions are believed to play an important role in the acceleration of 10 to 100 keV radiation belt electrons to MeV energies …
Cassini RADAR images at Hotei Arcus and western Xanadu, Titan: Evidence for geologically recent cryovolcanic activity
Lorenz, R. D.; Janssen, M. A.; Lunine, J. I. +14 more
Images obtained by the Cassini Titan Radar Mapper (RADAR) reveal lobate, flowlike features in the Hotei Arcus region that embay and cover surrounding terrains and channels. We conclude that they are cryovolcanic lava flows younger than surrounding terrain, although we cannot reject the sedimentary alternative. Their appearance is grossly similar t…
Periodicity in Saturn's magnetosphere: Plasma cam
Young, D. T.; Burch, J. L.; DeJong, A. D. +1 more
Plasma ion data from the Cassini Plasma Spectrometer (CAPS) are examined for all orbits from October 25, 2004 through Dec. 26, 2007. To eliminate effects of incomplete angular coverage, data are only used from the CAPS anode that is closest to viewing into the corotational flow and within 20° of that flow. The data are plotted in the SKR-based SLS…
Equatorward diffuse auroral emissions at Jupiter: Simultaneous HST and Galileo observations
Krupp, N.; Woch, J.; Menietti, J. D. +6 more
We study the auroral emissions equatorward of the main oval based on Hubble Space Telescope (HST) observations of both Jovian hemispheres on September 20, 1997. On the same day, Galileo observed changes in the electron pitch angle distribution between the inner and middle magnetosphere (PAD boundary), indicative of electron diffusion. This region,…
ACRIM-gap and TSI trend issue resolved using a surface magnetic flux TSI proxy model
Scafetta, Nicola; Willson, Richard C.
The ACRIM-gap (1989.5-1991.75) continuity dilemma for satellite TSI observations is resolved by bridging the satellite TSI monitoring gap between ACRIM1 and ACRIM2 results with TSI derived from Krivova et al.'s (2007) proxy model based on variations of the surface distribution of solar magnetic flux. `Mixed' versions of ACRIM and PMOD TSI composit…
Atmospheric origin of cold ion escape from Mars
Barabash, S.; Lundin, R.; Holmström, M. +4 more
Cold ionospheric ions dominate the plasma escape from Mars. The flow pattern versus altitude, latitude and local time suggests a fairly symmetric transport of ionospheric plasma from the dayside into the nightside/tail region of Mars. An interesting aspect of the plasma escape from Mars is the large abundance of molecular ions, implying that the o…
Non-dipolar solar wind structure observed in the cycle 23/24 minimum
Tokumaru, M.; Hayashi, K.; Kojima, M. +1 more
Interplanetary scintillation (IPS) observations made in the Cycle 23/24 minimum using the Solar-Terrestrial Environment Laboratory (STEL) multi-station system indicated that during intervals the solar wind had a significantly non-dipolar structure that consisted of fast wind components at the poles and the equator and slower wind components in bet…