Search Publications
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…
Ocean tides heat Enceladus
Tyler, R. H.
With a young, highly reflective surface and vigorous geological activity, Saturn's tiny moon Enceladus has been one of the most mysterious planetary bodies in the solar system. Recent observations from the Cassini spacecraft show vast plumes of vapor erupting from geysers near the south pole, and inferred heat fluxes of about 100 mW/m2 for the sam…
Fluvial network analysis on Titan: Evidence for subsurface structures and west-to-east wind flow, southwestern Xanadu
Burr, Devon M.; Mitchell, Karl L.; Jacobsen, Robert E. +3 more
Data of Titan's surface from the Cassini-Huygens mission show inferred fluvial networks interpreted as products of liquid alkane flow. Using synthetic aperture radar (SAR) data, we delineated drainage networks, measured network parameters, and used these measurements in a simplified algorithm for classifying terrestrial drainage patterns. The resu…
Disappearing induced magnetosphere at Venus: Implications for close-in exoplanets
Russell, C. T.; Lammer, H.; Zhang, T. L. +4 more
The solar wind interaction with a planetary atmosphere produces a magnetosphere-like structure near the planet whether or not the planet has an intrinsic global magnetic field. In the case of planets like Venus or Mars, which have no global intrinsic magnetic field but possess a significant atmosphere, a magnetosphere is induced in the highly cond…
Photometric changes on Saturn's Titan: Evidence for active cryovolcanism
Drossart, Pierre; Sotin, Christophe; Sicardy, Bruno +30 more
We report infrared spectrophotometric variability on the surface of Saturn's moon Titan detected in images returned by the Visual and Infrared Mapping Spectrometer (VIMS) onboard the Cassini Saturn Orbiter. The changes were observed at 7°S, 138°W and occurred between October 27, 2005 and January 15, 2006. After that date the surface was unchanged …
Electron density dropout near Enceladus in the context of water-vapor and water-ice
Gurnett, D. A.; Johnson, R. E.; Kurth, W. S. +4 more
On 12 March 2008, the Cassini spacecraft made a close encounter with the Saturnian moon Enceladus, passing within 52 km of the moon. The spacecraft trajectory was intentionally-oriented in a southerly direction to create a close alignment with the intense water-dominated plumes emitted from the south polar region. During the passage, the Cassini R…
One-hundred-km-scale basins on Enceladus: Evidence for an active ice shell
Schenk, Paul M.; McKinnon, William B.
Stereo-derived topographic mapping of ∼50% of Enceladus reveals at least 6 large-scale, ovoid depressions (basins) 90-175 km across and 800-to-1500 m deep and uncorrelated with geologic boundaries. In contrast, the south polar depression is larger and apparently shallower and correlates with active resurfacing. The shape and scale of the basins is…