Conditions allow surficial liquid flow on three bodies in the Solar System, Earth, Mars, and Titan. Evidence for surficial liquid flood flow has been observed on Earth and Mars. The mechanisms for generating flood flow vary according to the surficial conditions on each body. The most common flood-generating mechanism on Earth is wide-spread glaciation, which requires an atmospheric cycle of a v...

The future exploration of Mars is likely to utilize resources that can be extracted in situ. An overview of the geology of Mars has been presented and several mechanisms that could result in the formation of ore deposits have been identified. These include deposits caused by hydrothermal fluids resulting from volcanic activity, large igneous province formation and impact craters. Surface enrich...

We report the first radar soundings of the ionosphere of Mars with the MARSIS (Mars Advanced Radar for Subsurface and Ionosphere Sounding) instrument on board the orbiting Mars Express spacecraft. Several types of ionospheric echoes are observed, ranging from vertical echoes caused by specular reflection from the horizontally stratified ionosphere to a wide variety of oblique and diffuse echoes...

[1] Spatial variability of methane (CH4) on Mars suggests the presence of localized subsurface sources. Here, we show that olivine hydration in the Martian regolith and crust may be a major CH4 source, which contributed significantly to the warming of early Mars. Methane production is kinetically and thermodynamically favored during low-T aqueous alteration of olivine-rich rocks. Sustained rele...

Microtubule-associated proteins (MAPs) ensure the fidelity of chromosome segregation by controlling microtubule (MT) dynamics and mitotic spindle stability. However, many aspects of MAP function and regulation are poorly understood in a developmental context. We show that mars, which encodes a Drosophila melanogaster member of the hepatoma up-regulated protein family of MAPs, is essential for M...

Despite radically different environmental conditions, terrestrial and martian dunes bear a strong resemblance, indicating that the basic processes of saltation and grainfall (sand avalanching down the dune slipface) operate on both worlds. Here, we show that martian dunes are subject to an additional modification process not found on Earth: springtime sublimation of Mars' CO(2) seasonal polar c...

This paper focusses on the estimation of exterior orientation parameters of the High Resolution Stereo Camera (HRSC) orbiting planet Mars during the European Mars Express mission since January 2004. One of the challenges for the photogrammetric processing of HRSC images is the low number of Ground Control Points (GCPs) on Mars which can be identified and measured in the images in the usual way....

Coupling between the lower and upper atmosphere, combined with loss of gas from the upper atmosphere to space, likely contributed to the thin, cold, dry atmosphere of modern Mars. To help understand ongoing ion loss to space, the Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft made comprehensive measurements of the Mars upper atmosphere, ionosphere, and interactions with the Sun and s...

Introduction: The topography of Mars remained unknown until the first orbiting spacecraft, since early ground-based observations of Mars displayed only variations due to albedo which correspond to changes in surface composition and texture rather than changes in surface altitude. However a technique was being developed in the late 1960s and early 1970s to determine the Martian topography by mea...

We apply a model for sand dunes to calculate formation of dunes on Mars under the present Martian atmospheric conditions. We find that different dune shapes as those imaged by Mars Global Surveyor could have been formed by the action of sand-moving winds occuring on today’s Mars. Our calculations show, however, that Martian dunes could be only formed due to the higher efficiency of Martian wind...