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Cometary ions detected by the Cassini spacecraft 6.5 au downstream of Comet 153P/Ikeya-Zhang
Jones, G. H.; McComas, D. J.; Smith, E. J. +5 more
During March-April 2002, while between the orbits of Jupiter and Saturn, the Cassini spacecraft detected a significant enhancement in pickup proton flux. The most likely explanation for this enhancement was the addition of protons to the solar wind by the ionization of neutral hydrogen in the corona of comet 153P/Ikeya-Zhang. This comet passed rel…
An insight to the cryospheric level in Mars: Case study from the Thaumasia Minor
Dasgupta, Dipayan; Kundu, Abhik; Dasgupta, Nilanjan
The presence of a subsurface Martian cryosphere has been widely acknowledged. Rampart craters and outflow channels are thought to be the prominent geomorphic signatures in support of the presence of this cryospheric layer. Valley networks, on the other hand, are thought to be the signatures of precipitation, seasonal meltwater flow due to glacial …
Probable ice-rich deposits on north-facing slopes in Alba Patera, Mars
Gregg, Tracy K. P.; Schiff, Nicholas L. G.
We examine unconformable lobate deposits along the north-facing slopes of Alba Patera (40°N, 250°E with an elevation of ~6 km), Mars, using data from the Mars Reconnaissance Orbiter Context Camera, High-Resolution Imaging Science Experiment, and the Mars Orbiter Laser Altimeter. We interpret the lobate north-facing slope deposits (NSFDs) to be sma…
Simulated SPHEREx spectra of asteroids and their implications for asteroid size and reflectance estimation
Doré, Olivier; Ivezić, Željko; Ivezić, Vedrana +6 more
We describe the construction and analysis of simulated SPHEREx spectra of Main Belt and Trojan asteroids. SPHEREx will deliver the first all-sky spectral survey at 96 spectral channels between 0.75 µm and 5.0 µm. We have developed a method for correcting SPHEREx asteroid spectra for intrinsic rotational variability that does not requir…
Noble gases in Dome C micrometeorites - An attempt to disentangle asteroidal and cometary sources
Trieloff, Mario; Engrand, Cécile; Duprat, Jean +2 more
We have performed a comprehensive noble gas study, including the isotopes of krypton and xenon, on a set of micrometeorites (MMs) collected from surface snow at Dome C (DC) on the Antarctic plateau. He and Ne are generally dominated by a solar component, with lower 4He concentrations and 4He/20Ne ratios in crystall…
Titan's haze at opposite seasons from HST-STIS spectroscopy
Karkoschka, Erich
We present an analysis of three new image cubes of Titan by the Space Telescope Imaging Spectrograph taken in 2017, 2018, and 2019, half a Titan year after previously analyzed image cubes. Both data sets probe periods when Titan's seasonal north-south-asymmetry switched. The new observations show that the new reversal came exactly half a Titan yea…
Ma'adim Vallis, Mars: Insights into episodic and late-stage water activity from an impact crater
Harish; Vijayan, S.; Tuhi, S. +4 more
Alluvial fans, a form of sedimentary deposit reported on Mars, offer insight into the evolution and nature of fluvial activity on the planet. Additionally, the region's preserved mineralogy can also be used to study its hydrological history. In this context, we discuss the diverse geomorphology and mineralogy of an unnamed crater that formed on th…
Sub-field of view surface thermal modeling of Cassini CIRS observations of Rhea during south polar winter
Howett, Carly J. A.; Miles, Georgina; Spencer, John +1 more
Rhea's exosphere is thought to originate from sources of carbon, water ice and other volatiles that arrived at Rhea by bombardment. Its seasonal variability is directly driven by polar surface temperatures allowing surface adsorption, and the persistence of source volatiles require that seasonal temperatures remain sufficiently cold to retain them…
From hot to cold? - Hydrothermal activities as a source for icy-debris flows on Dryas Mons, Terra Sirenum, Mars
Hauber, E.; Martin, P.; Cardesín-Moinelo, A. +3 more
During an extensive grid-mapping campaign on Mars' southern hemisphere, we have detected so-called sheet flow deposits, which are defined by distinctive lobate fronts, thin and mostly planar layers, and faint sub-parallel surface lineations. They originate from the high plains of Dryas Mons, a large massif of impact and tectonic origin, and follow…
Search for shallow subsurface structures in Chryse and Acidalia Planitiae on Mars
Tsuchiya, Fuminori; Kimura, Tomoki; Kumamoto, Atsushi +6 more
Chryse and Acidalia Planitiae (CAP) are known as one of the areas which have abundant sites of recurring slope lineae (RSL) on Mars. We present a radar survey of shallow subsurface structures across the CAP regions using the Mars SHAllow RADar sounder (SHARAD) onboard the Mars Reconnaissance Orbiter (MRO). A total of 25 subsurface reflectors were …