Search Publications
Polar and mid-latitude vortices and zonal flows on Jupiter and Saturn
Yadav, Rakesh K.; Featherstone, Nicholas A.; Aurnou, Jonathan M. +1 more
Zonal flow on Jupiter and Saturn consists of equatorial super-rotation and alternating East-West jet streams at higher latitudes. Interacting with these zonal flows, numerous vortices occur with various sizes and lifetimes. The Juno mission and Cassini's grand finale have shown that the zonal jets of Jupiter and Saturn extend deeply into their mol…
Evidence of surface heterogeneity on active asteroid (3200) Phaethon
Granvik, Mikael; MacLennan, Eric; Marshall, Sean
Thermal infrared emission and thermophysical modeling techniques are powerful tools in deciphering the surface properties of asteroids. The near-Earth asteroid (3200) Phaethon is an active asteroid with a very small perihelion distance and is likely the source of the Geminid meteor shower. Using a thermophysical model with a non-convex shape of Ph…
Convective storms in closed cyclones in Jupiter's South Temperate Belt: (I) observations
Wong, Michael H.; Baines, Kevin H.; Hueso, Ricardo +19 more
On May 31, 2020 a short-lived convective storm appeared in one of the small cyclones of Jupiter's South Temperate Belt (STB) at planetographic latitude 30.8°S. The outbreak was captured by amateur astronomer Clyde Foster in methane-band images, became widely known as Clyde's Spot, and was imaged at very high resolution by the Junocam instrument on…
Presence of clay minerals can obscure spectral evidence of Mg sulfates: implications for orbital observations of Mars
Milliken, Ralph E.; Sheppard, Rachel Y.; Robertson, Kevin M.
The martian crust is often viewed through the lens of its dominant secondary minerals, Noachian phyllosilicates and Hesperian sulfates, based on orbital spectral observations. However, the effects of surface exposure on the spectra of these hydrous minerals are not fully understood. We use an environmental chamber to measure changes in near-infrar…
Photochemistry of HCl in the martian atmosphere
Krasnopolsky, Vladimir A.
The recent discovery of HCl in the martian atmosphere using the ExoMars Trace Gas Orbiter (Korablev et al., 2021, Sci. Adv. 7, eabe4386) during a global dust storm indicates a correlation between the HCl appearance and dust. Here this idea is studied using one-dimensional photochemical modeling on two summer midlatitude sites in the aphelion and p…
Circum-Tharsis wrinkle ridges at Lunae Planum: Morphometry, formation, and crustal implications
Karagoz, Oguzcan; Kenkmann, Thomas; Wulf, Gerwin
Wrinkle ridges are one of the most widespread tectonic landforms on Mars developed under a compressional stress regime within the lithosphere. In this study, we investigate the morphology and structure of wrinkle ridges at northern Lunae Planum, which belongs to the circum-Tharsis wrinkle ridge system. We use methods to construct balanced cross-se…
The lithified aeolian dune field adjacent to the Apollinaris Sulci, Mars: Geological history and paleo-wind record
Chojnacki, Matthew; Edgett, Kenneth S.; Day, Mackenzie +1 more
A lithified aeolian dune field in the Apollinaris Sulci region of Mars presents a unique opportunity to study ancient aeolian processes and paleo-wind conditions during an earlier episode of martian climate history. The ancient dunes occur inside an eroded, partly-filled impact structure. The petrified dune field retains its original geomorphology…
Explosive volcanism in Noctis Fossae on Mars
Pieterek, B.; Laban, M.; Ciążela, J. +1 more
Based on theoretical considerations, basaltic volcanism of explosive character should be common on Mars. Although the record of explosive volcanic fields on Mars continues to grow, many unexplored volcanic fields remain. In this research, we identified a group of 25 volcanic cones and associated lava flows emplaced in the Noctis Fossae region on M…
Constraining the formation of paleolake inlet valleys across crater rims
Goudge, Timothy A.; Fassett, Caleb I.; Osinski, Gordon R. +1 more
Impact crater lakes with an inlet valley were common on Mars during past epochs. However, it has not been established exactly how impact craters with initially high-standing rims were breached by an inlet. We investigated four potential mechanisms for inlet valley breach formation: (1) rim erosion, (2) depositional rim burial, (3) drainage head er…
Modelling reconstruction and boulder size-frequency distribution of a young (<5 Myr) landslide located in Simud Vallis floor, Mars
Lucchetti, Alice; Pajola, Maurizio; Cremonese, Gabriele +8 more
We focus on a young (~ 4.5 Ma), 3.4 km long landslide located in the floor of Simud Vallis, Oxia Palus Quadrangle of Mars. By making use of a 2 m-scale HiRISE DEM we reconstruct the terrain surface before the landslide and in doing so we estimate the release and deposition heights and volumes related to the different stages of the landslide. Using…