Search Publications
Evidence for fluvial and glacial activities within impact craters that excavated into a Noachian volcanic dome on Mars
Harish; Vijayan, S.; Mangold, N.
Impact craters on Mars preserve diverse records of volcanic, fluvial, and glacial activities. Enigmatically, the preservation of these major activities or records altogether within impact craters is rare. We report one such new observation of impact craters that formed on a volcanic dome studied using data from the Mars Reconnaissance Orbiter's (M…
Neptune's HCl upper limit from Herschel/HIFI
Irwin, P. G. J.; Teanby, N. A.; Gould, B.
Here we search for hydrogen chloride (HCl) in Neptune's stratosphere using observations of the 1876.22 GHz J=3-2 transition from the Heterodyne Instrument for the Far-Infrared (HIFI) on Herschel. Observations comprise a 7.2 hr disc-averaged integration, originally designed to investigate stratospheric methane. Significant HCl emission was not dete…
Forbidden atomic oxygen emissions in the Martian dayside upper atmosphere
Bhardwaj, Anil; Jain, Sonal Kumar; Raghuram, Susarla
Recently, Nadir and Occultation for Mars Discovery (NOMAD) ultraviolet and visible spectrometer instrument on board the European Space Agency's ExoMars Trace Gas Orbiter (TGO) simultaneously measured the limb emission intensities for both [OI] 2972 and 5577 Å (green) emissions in the dayside of Martian upper atmosphere. But the atomic oxygen red-d…
Multiscale spectral discrimination of poorly crystalline and intermixed alteration phases using aerial and ground-based ExoMars rover emulator data
Allender, E. J.; Cousins, C. R.; Gunn, M. D. +1 more
A key goal of the ExoMars rover Rosalind Franklin is to analyze accessible hydrated mineral deposits using panoramic multiscale and multispectral imagery. We conducted a multiscale spectroscopic study on hydrothermally-altered basalt-hosted soils in the geothermal area of Námafjall in northern Iceland. Basaltic lavas here that have experienced fir…
Comet 21P/Giacobini-Zinner: Water production activity over 20 years with SOHO/SWAN
Bertaux, J. -L.; Combi, M. R.; Quémerais, E. +3 more
In 1985 Comet 21P/Giacobini-Zinner was the first comet visited by a spacecraft, the International Cometary Explorer (ICE) satellite, several months before the armada of Halley spacecraft had their encounters in 1986. ICE was originally the ISEE-3 satellite, designed for magnetospheric measurements near the Earth, and was diverted via a lunar gravi…
Sizes of the smallest particles at Saturn's ring edges
Colwell, Joshua E.; Esposito, Larry W.; Becker, Tracy M. +1 more
The Ultraviolet Imaging Spectrograph (UVIS) on the Cassini spacecraft observed 275 ring stellar occultations from July 2004 until August 2017. We use stellar occultation data from the UVIS High Speed Photometer (HSP) to characterize the smallest particles at ring edges by modeling observed diffraction signatures. We identify these signatures as sp…
Constraining the surface properties of Helene
Royer, E.; Howett, C. J. A.
We analyze two sets of observations of Dione's co-orbital satellite Helene taken by Cassini's Composite Infrared Spectrometer (CIRS). The first observation was a CIRS FP3 (600 to 1100 cm-1, 9.1 to 16.7 µm) stare of Helene's trailing hemisphere, where two of the ten FP3 pixels were filled. The daytime surface temperatures derived f…
Characterizing southern portion of Mare Vaporum with improved Chandrayaan-1 M3 data
Videen, Gorden; Shkuratov, Yuriy; Surkov, Yehor +3 more
We investigate a southern portion of Mare Vaporum using Chandrayaan-1 M3 images for which we suppress striped noise. Additional data processing allows us to analyze such spectral parameters as the depths and positions of the absorption bands near 1 and 2 µm. Mineral types were mapped using the cluster analysis of Adams diagram for…
Venus night-side photometry with "cleaned" Akatsuki/IR2 data: Aerosol properties and variations of carbon monoxide
Sato, Takao M.; Satoh, Takehiko; Horinouchi, Takeshi +2 more
We have developed a novel method called Restoration by Simple Subtraction (RSS) to clean and restore the Venus night-side disk in "contaminated" Akatsuki/IR2 images at 2.26 and 1.735 µm. Light spread from the intense day crescent is cancelled by subtracting a near-simultaneous 2.32-µm image (scaled) from a 2.26-µm image. Net-cont…
Martian roughness analogues of Europan terrains for radar sounder investigations
Gerekos, Christopher; Grima, Cyril; Steinbrügge, Gregor +5 more
Understanding the implications of Europa's roughness on backscattered radar signals is central to ensure that the future radar sounding instruments heading for the Jovian icy moons, the Radar for Icy Moons Exploration (RIME) and the Radar for Europa Assessment and Sounding: Ocean to Near-surface (REASON), will yield fruitful observations over thei…