Related papers: A lower-than-expected saltation threshold at Marti…
The orbital motions and spin-axis rotations of extended bodies are traditionally considered to be coupled only by tidal mechanisms. The orbit-spin coupling hypothesis supplies an additional mechanism. A reversing torque on rotating extended…
We report an experimental study of a binary sand bed under an oscillating water flow. The formation and evolution of ripples is observed. The appearance of a granular segregation is shown to strongly depend on the sand bed preparation. The…
The Martian climate is governed by an annual cycle, that results in the condensation of CO$_{2}$ ice during winter, up to a meter thick at the pole and thousands of kilometers in extension. Water and dust may be trapped during the…
Recent findings suggest Mars may have been a clement environment for the emergence of life, and may even have compared favorably to Earth in this regard. These findings have revived interest in the hypothesis that prebiotically important…
Early Mars climate research has well-defined goals (Mars Exploration Program Analysis Group 2018). Achieving these goals requires geologists and climate modelers to coordinate. Coordination is easier if results are expressed in terms of…
Despite decades of scientific research on the subject, the climate of the first 1.5 Gyr of Mars history has not been fully understood yet. Especially challenging is the need to reconcile the presence of liquid water for extended periods of…
First high-altitude observations of gravity wave (GW)-induced CO$_2$ density perturbations in the Martian thermosphere retrieved from NASA's NGIMS instrument on board the MAVEN satellite are presented and interpreted using the extended GW…
Motivated by the important role of the ocean in the Earth climate system, here we investigate possible scenarios of ocean circulations on exoplanets using a one-layer shallow water ocean model. Specifically, we investigate how planetary…
It is widely accepted that both ripples and dunes form in rivers by primary linear instability, the wavelength of the former scaling on the grain size, that of the latter being controled by the water depth. We revisit here this problem,…
The formation mechanism of tidal dwarf galaxies means they are expected to contain little or no dark matter. As such, they might be expected to be very sensitive to their environment. We investigate the impact of ram pressure on tidal dwarf…
Martin and Kok (2018a) measured two distinct aeolian saltation transport thresholds: a larger threshold below which continuous saltation transport becomes intermittent and a smaller threshold below which intermittent saltation transport…
An experimental study of a binary granular mixture submitted to a transient shear flow in a cylindrical container is reported. The formation of ripples with a spiral shape is observed. The appearance of phase segregation in those spiral…
Reconciling the geology of Mars with models of atmospheric evolution remains a major challenge. Martian geology is characterized by past evidence for episodic surface liquid water, and geochemistry indicating a slow and intermittent…
Aims: To investigate the stability and angular momentum transport by the strato-rotational instability in the nonlinear regime. Methods: The hydrodynamic compressible equations are solved in a cartesian box in which the outer cylinder is…
At large scales, the Reynolds stress tensor exhibits notable anisotropy, a key feature of all wall-bounded turbulent flows. Yet, how the drivers of this anisotropy evolve with shearing and thermal stratification in the atmospheric surface…
Ancient hydrology is recorded by sedimentary rocks on Mars. The most voluminous sedimentary rocks that formed during Mars' Hesperian period are sulfate-rich rocks, explored by the $Opportunity$ rover from 2004-2012 and soon to be…
Sand patches are one of the precursors to early-stage protodunes and occur widely in both desert and coastal aeolian environments. Here we show field evidence of a mechanism to explain the initiation of sand patches on non-erodible…
Observations and meteorites indicate that the Martian materials are enigmatically distributed within the inner solar system. A mega impact on Mars creating a Martian hemispheric dichotomy and the Martian moons can potentially eject Martian…
Seasonal flows on warm slopes, or recurring slope lineae ("RSL"), have been presented as strong evidence for currently flowing water on Mars. This assumption was supported by a correlation between activity and warm temperatures, and by the…
We use a 3D general circulation model to compare the primitive Martian hydrological cycle in "warm and wet" and "cold and icy" scenarios. In the warm and wet scenario, an anomalously high solar flux or intense greenhouse warming…