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Dust aerosol, clouds, and the atmospheric optical depth record over 5 Mars years of the Mars Exploration Rover mission
Lemmon, Mark T.; Smith, Michael D.; Bell, James F., III +3 more
Dust aerosol plays a fundamental role in the behavior and evolution of the martian atmosphere. The first five Mars years of Mars Exploration Rover data provide an unprecedented record of the dust load at two sites. This record is useful for characterization of the atmosphere at the sites and as ground truth for orbital observations. Atmospheric ex…
The orbits and masses of satellites of Pluto
Showalter, Mark R.; Buie, Marc W.; Jacobson, Robert A. +1 more
We present the numerically integrated orbits of Pluto's satellites. The orbits have been fit to a data set that includes Earth-based and Hubble Space Telescope (HST) astrometry of Charon, Nix, Hydra, Kerberos, and Styx, as well as the lightcurves from the Pluto-Charon mutual events. We also report new, 2010-2012 HST astrometry of all satellites in…
Record-breaking storm activity on Uranus in 2014
de Pater, Imke; Sromovsky, L. A.; Fry, P. M. +3 more
In spite of an expected decline in convective activity following the 2007 equinox of Uranus, eight sizable storms were detected on the planet with the near-infrared camera NIRC2, coupled to the adaptive optics system, on the 10-m W.M. Keck telescope on UT 5 and 6 August 2014. All storms were on Uranus' northern hemisphere, including the brightest …
Detection of Callisto's oxygen atmosphere with the Hubble Space Telescope
France, Kevin; Feldman, Paul D.; Strobel, Darrell F. +3 more
We report the result of a search for evidence of an O2-dominated atmosphere on Callisto, using the high far-ultraviolet sensitivity of the Hubble Space Telescope Cosmic Origins Spectrograph (COS). Observations of Callisto's leading/Jupiter-facing hemisphere show, for the first time, variable-strength atomic oxygen (O I) emissions with b…
Coordinated Hubble Space Telescope and Venus Express Observations of Venus' upper cloud deck
Bertaux, Jean-Loup; Marcq, Emmanuel; Wilson, Colin +10 more
Hubble Space Telescope Imaging Spectrograph (HST/STIS) UV observations of Venus' upper cloud tops were obtained between 20N and 40S latitude on December 28, 2010; January 22, 2011 and January 27, 2011 in coordination with the Venus Express (VEx) mission. The high spectral (0.27 nm) and spatial (40-60 km/pixel) resolution HST/STIS data provide the …
High S/N Keck and Gemini AO imaging of Uranus during 2012-2014: New cloud patterns, increasing activity, and improved wind measurements
Sromovsky, L. A.; Fry, P. M.; Hammel, H. B. +2 more
We imaged Uranus in the near infrared from 2012 into 2014, using the Keck/NIRC2 camera and Gemini/NIRI camera, both with adaptive optics. We obtained exceptional signal to noise ratios by averaging 8-16 individual exposures in a planet-fixed coordinate system. These noise-reduced images revealed many low-contrast discrete features and large scale …
Interannual and seasonal changes in the north polar ice deposits of Mars: Observations from MY 29-31 using MARCI
James, P. B.; Cantor, B. A.; Calvin, W. M. +1 more
The MARCI camera on the Mars Reconnaissance Orbiter provides daily synoptic coverage that allows monitoring of seasonal cap retreat and interannual changes that occur between Mars year (MY) and over the northern summer. The northern seasonal cap evolution was observed in MY 29, 30 and 31 (12/2007-04/2012). Observation over multiple Mars years allo…
The mutual orbit, mass, and density of the large transneptunian binary system Varda and Ilmarë
Roe, H. G.; Trujillo, C. A.; Thirouin, A. +7 more
From observations by the Hubble Space Telescope, Keck II Telescope, and Gemini North Telescope, we have determined the mutual orbit of the large transneptunian object (174567) Varda and its satellite Ilmarë. These two objects orbit one another in a highly inclined, circular or near-circular orbit with a period of 5.75 days and a semimajor axis of …
Linking Europa's plume activity to tides, tectonics, and liquid water
Roth, Lorenz; Rhoden, Alyssa Rose; Retherford, Kurt +1 more
Much of the geologic activity preserved on Europa's icy surface has been attributed to tidal deformation, mainly due to Europa's eccentric orbit. Although the surface is geologically young (30-80 Myr), there is little information as to whether tidally-driven surface processes are ongoing. However, a recent detection of water vapor near Europa's so…
Spatially resolved HST/STIS observations of Io's dayside equatorial atmosphere
Spencer, John R.; Jessup, Kandis Lea
We report on an investigation of the spatial distribution of Io's atmosphere, and its diurnal variability, using Hubble's Space Telescope Imaging Spectrograph (HST/STIS). From December 2010 to January 2012, we obtained spatially resolved limb-to-limb 2100-3100 Å spectra at low latitudes (<30°), with the STIS 0.1″ slit. Spectra taken at two cent…