Search Publications
Total solar irradiance during the Holocene
Beer, J.; Steinhilber, F.; Fröhlich, C.
For the first time a record of total solar irradiance covering 9300 years is presented, which covers almost the entire Holocene. This reconstruction is based on a recently observationally derived relationship between total solar irradiance and the open solar magnetic field. Here we show that the open solar magnetic field can be obtained from the c…
Radar evidence for ice in lobate debris aprons in the mid-northern latitudes of Mars
Head, James W.; Frigeri, Alessandro; Seu, Roberto +5 more
Subsurface radar sounding data indicate that lobate debris aprons found in Deuteronilus Mensae in the mid-northern latitudes of Mars are composed predominantly of water ice. The position in time delay and the relatively low amount of signal loss of the apparent basal reflectors below the debris aprons indicate that aprons contain only a minor comp…
Solar Irradiance Reference Spectra (SIRS) for the 2008 Whole Heliosphere Interval (WHI)
Chamberlin, Phillip C.; Woods, Thomas N.; Eparvier, Francis G. +6 more
The IHY2007 Whole Heliosphere Interval (WHI) for solar Carrington Rotation 2068 (20 March to 16 April 2008) has been very successful in obtaining a wide variety of solar, heliospheric, and planetary observations during times of solar cycle minimum conditions. One of these efforts is the generation of solar irradiance reference spectra (SIRS) from …
Cassini imaging of Titan's high-latitude lakes, clouds, and south-polar surface changes
West, R. A.; Porco, C. C.; McEwen, A. S. +5 more
Cassini's Imaging Science Subsystem (ISS) has been observing Titan since April 2004, compiling a nearly global surface map and monitoring the surface and atmosphere for activity. Early images of the south-polar region revealed numerous dark surface features and contemporaneous convective cloud systems, suggesting the presence of hydrocarbon lakes …
Discovery of a north-south asymmetry in Saturn's radio rotation period
Gurnett, D. A.; Persoon, A. M.; Kurth, W. S. +5 more
For many years it has been known that Saturn emits intense radio emissions at kilometer wavelengths and that this radiation is modulated by the rotation of the planet at a rate that varies by up to one percent on a time scale of years. Recent radio observations from the Cassini spacecraft have revealed the appearance of a second component, with a …
Global pattern of Titan's dunes: Radar survey from the Cassini prime mission
Lorenz, Ralph D.; Radebaugh, Jani
We present a map of the orientation and extent of Titan's sand dunes derived from the complete radar imaging dataset from the Cassini prime mission. The 16,000 dune segments we have mapped cover ~8% of the Titan's surface (suggesting a total coverage of ~20%), are confined within 30° of the equator, and show local and regional deviations of dune o…
Anomalous magnetosheath flows and distorted subsolar magnetopause for radial interplanetary magnetic fields
Glassmeier, K. H.; Plaschke, F.; McFadden, J. P. +5 more
On 12 August 2007 from 1436 to 1441 UT, when the five THEMIS probes (THA, THB, THC, THD, and THE) were located near the subsolar magnetopause, a sunward flow was observed in the magnetosheath. A fast anti-sunward flow (-280 km/s) was observed in the magnetosheath before the sunward flow. Although THA observed this fast anti-sunward flow, THC and T…
Phyllosilicates and sulfates at Endeavour Crater, Meridiani Planum, Mars
Arvidson, R. E.; Mustard, J. F.; Wray, J. J. +5 more
Phyllosilicates have been identified on the Martian surface from orbit, and are hypothesized to have formed under wet, non-acidic conditions early in the planet's history. Exposures of these minerals have not yet been examined by a landed mission. Using Mars Reconnaissance Orbiter data, we report the detection of phyllosilicate-bearing outcrops th…
Fine jet structure of electrically charged grains in Enceladus' plume
Lewis, G. R.; Coates, A. J.; Russell, C. T. +18 more
By traversing the plume erupting from high southern latitudes on Saturn's moon Enceladus, Cassini orbiter instruments can directly sample the material therein. Cassini Plasma Spectrometer, CAPS, data show that a major plume component comprises previously-undetected particles of nanometer scales and larger that bridge the mass gap between previousl…
Discrete classification and electron energy spectra of Titan's varied magnetospheric environment
Coates, A. J.; Smith, H. T.; Young, D. T. +2 more
We analyse combined electron spectra across the dynamic range of both Cassini electron sensors in order to characterise the background plasma environment near Titan for 54 Cassini-Titan encounters as of May 2009. We characterise the encounters into four broad types: Plasma sheet, Lobe-like, Magnetosheath and Bimodal. Despite many encounters occurr…