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New Evidence for a Water-Rich History on Mars

Mars may have been a wetter place than previously thought, according to research on simulated Martian meteorites conducted, in part, at the Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab).
In a study published today in the journal Nature Communications, researchers found evidence that a mineral found in Martian meteorites - which had been considered as proof of an ancient dry environment on Mars - may have originally been a hydrogen-containing mineral that could indicate a more water-rich history for the Red Planet.

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Some Ancient Mars Lakes Came Long After Others

Lakes and snowmelt-fed streams on Mars formed much later than previously thought possible, according to new findings using data primarily from NASA's Mars Reconnaissance Orbiter.
The recently discovered lakes and streams appeared roughly a billion years after a well-documented, earlier era of wet conditions on ancient Mars. These results provide insight into the climate history of the Red Planet and suggest the surface conditions at this later time may also have been suitable for microbial life.

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Martian hydrological cycle
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Title: Comparison of "warm and wet" and "cold and icy" scenarios for early Mars in a 3D climate model
Author: Robin D. Wordsworth, Laura Kerber, Raymond T. Pierrehumbert, Francois Forget, James W. Head

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 artificially added to the climate model are required to maintain warm conditions and an ice-free northern ocean. Precipitation shows strong surface variations, with high rates around Hellas basin and west of Tharsis but low rates around Margaritifer Sinus (where the observed valley network drainage density is nonetheless high). In the cold and icy scenario, snow migration is a function of both obliquity and surface pressure, and limited episodic melting is possible through combinations of seasonal, volcanic and impact forcing. At surface pressures above those required to avoid atmospheric collapse (~0.5 bar) and moderate to high obliquity, snow is transported to the equatorial highland regions where the concentration of valley networks is highest. Snow accumulation in the Aeolis quadrangle is high, indicating an ice-free northern ocean is not required to supply water to Gale crater. At lower surface pressures and obliquities, both H2O and CO2 are trapped as ice at the poles and the equatorial regions become extremely dry. The valley network distribution is positively correlated with snow accumulation produced by the cold and icy simulation at 41.8 degrees obliquity but uncorrelated with precipitation produced by the warm and wet simulation. Because our simulations make specific predictions for precipitation patterns under different climate scenarios, they motivate future targeted geological studies.

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NASA Research Suggests Mars Once Had More Water than Earth's Arctic Ocean

A primitive ocean on Mars held more water than Earth's Arctic Ocean, according to NASA scientists who, using ground-based observatories, measured water signatures in the Red Planet's atmosphere.
Scientists have been searching for answers to why this vast water supply left the surface. Details of the observations and computations appear in Thursday's edition of Science magazine.

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Curiosity Mars Rover Sees Trend in Water Presence

NASA's Mars rover Curiosity has seen evidence of water-bearing minerals in rocks near where it had already found clay minerals inside a drilled rock.
Last week, the rover's science team announced that analysis of powder from a drilled mudstone rock on Mars indicates past environmental conditions that were favourable for microbial life. Additional findings presented today (March 18) at a news briefing at the Lunar and Planetary Science Conference in The Woodlands, Texas, suggest those conditions extended beyond the site of the drilling.
 
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Mars rover Curiosity sees key water indicator

The US space agency (Nasa) has reported that its Curiosity rover has made another significant discovery on Mars.
The robot has drilled into a rock that contains clay minerals - an indication of formation in, or substantial alteration by, neutral water.
 
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Meteorites reveal warm water existed on Mars

The study determined that water temperatures on the Red Planet ranged from 50°C to 150°C. Microbes on Earth can live in similar waters, for example in the volcanic thermal springs at Yellowstone Park, the scientists behind the research point out.
The research is based on detailed scrutiny of Mars meteorites on Earth using powerful microscopes in the University of Leicester Department of Physics and Astronomy. This was followed-up by computer modelling work at The Open University.

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Exhumed rocks reveal Mars water ran deep

By studying rocks blasted out of impact craters, ESA's Mars Express has found evidence that underground water persisted at depth for prolonged periods during the first billion years of the Red Planet's existence.
Impact craters are natural windows into the history of planetary surfaces - the deeper the crater, the further back in time you can probe.

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 Extensive Water in Mars Interior

Until now, Earth was the only planet known to have vast reservoirs of water in its interior. Scientists analysed the water content of two Martian meteorites originating from inside the Red Planet. They found that the amount of water in places of the Martian mantle is vastly larger than previous estimates and is similar to that of Earth's. The results not only affect what we know about the geologic history of Mars, but also have implications for how water got to the Martian surface. The data raise the possibility that Mars could have sustained life.
The research was led by former Carnegie postdoctoral scientist Francis McCubbin, now at the University of New Mexico. The analysis was performed by Carnegie Institution investigator Erik Hauri and team and is published in the journal Geology.

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Title: Dielectric map of the Martian northern hemisphere and the nature of plain filling materials
Authors: Jérémie Mouginot, Antoine Pommerol, Pierre Beck, Wlodek Kofman, Stephen M. Clifford

A number of observations suggest that an extended ocean once covered a significant part of the Martian northern hemisphere. By probing the physical properties of the subsurface to unprecedented depth, the MARSIS/Mars Express provides new geophysical evidences for the former existence of a Late Hesperian ocean. The Vastitas Borealis formation, located inside a putative shoreline of the ancient ocean, has a low dielectric constant compared with that of typical volcanic materials. We show that the measured value is only consistent with low-density sedimentary deposits, massive deposits of ground-ice, or a combination of the two. In contrast, radar observations indicate a distribution of shallow ground ice in equilibrium with the atmosphere in the south polar region. We conclude that the northern plains are filled with remnants of a late Hesperian ocean, fed by water and sediments from the outflow channels about 3 Gy ago.

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