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Posts Tagged ‘geology’

Vesta’s Rocky History


© NASA/JPL - Caltech / UCLA / MPS / DLR / IDA

© NASA/JPL – Caltech / UCLA / MPS / DLR / IDA

Rocks are silent storytellers: because each mineral is created only under certain conditions, they provide insight into the evolution of the body on which they are found. Scientists from the Max Planck Institute for Solar System Research (MPS) in Germany have now begun to tell such a story from the enigmatic dark material discovered on the protoplanet Vesta. Using data from the framing camera aboard NASA’s Dawn spacecraft, the researchers have succeeded for the first time in identifying a mineral component of this material: serpentine. The new discovery puts an end to the discussion about the origin of the dark material: impacts of primitive asteroids must have distributed it on Vesta.

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Curiosity Travels Through Ancient Glaciers On Mars


Credit: CTX-MRO-NASA

Credit: CTX-MRO-NASA

NASA’s Mars Curiosity Rover has completed a Martian year –687 Earth days– this week. The vehicle travels through an arid and reddish landscape that was home to glaciers in the past. Ancient Mars held large quantities of water, yet its global hydro-geological cycles were very cold, so much so that they induced the presence of a giant ocean, partially ice-covered and rimmed by glaciers on the lower plains of the northern hemisphere.

Now, an international team of researchers has confirmed this global picture locally, on the Martian site where Curiosity is roving: Gale crater. “This crater was covered by glaciers approximately 3,500 million years ago, which were particularly extensive on its central mound, Aeolis Mons” points to SINC the lead investigator of the study Alberto Fairén, from the Centro de Astrobiología (INTA-CSIC) in Spain and Cornell University in the USA.

“However, at that time there were also rivers and lakes with very cold liquid water in the lower-lying areas within the crater,” adds the researcher, who highlights the fact that ancient Mars was capable of “maintaining large quantities of liquid water (an essential element for life) at the same time that giant ice sheets covered extensive regions of its surface”.

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55-Year-Old Dark Side Of The Moon Mystery Solved


Image: NASA

Image: NASA

The “man in the moon” appeared when meteoroids struck the Earth-facing side of the moon creating large flat seas of basalt that we see as dark areas called maria. But no “face” exists on farside of the moon and now, Penn State astrophysicists think they know why.

This mystery is called the Lunar Farside Highlands Problem and dates back to 1959, when the Soviet spacecraft Luna 3 transmitted the first images of the dark side of the moon back to Earth. It was called the dark side because it was unknown, not because sunlight does not reach it. Researchers immediately noticed that fewer “seas” or maria existed on this portion of the moon that always faces away from Earth.

Wright, Steinn Sigurdsson, professor of astrophysics and Arpita Roy, graduate student in astronomy and astrophysics, and lead author of the study, realized that the absence of maria, which is due to a difference in crustal thickness between the side of the moon we see and the hidden side, is a consequence of how the moon originally formed. The researchers report their results in today’s (June 9) Astrophysical Journal Letters.

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A Habitable Environment On Martian Volcano?


The slopes of a giant Martian volcano, once covered in glacial ice, may have been home to one of the most recent habitable environments yet found on the Red Planet, according to new research led by Brown University geologists.

Nearly twice as tall as Mount Everest, Arsia Mons is the third tallest volcano on Mars and one of the largest mountains in the solar system. This new analysis of the landforms surrounding Arsia Mons shows that eruptions along the volcano’s northwest flank happened at the same time that a glacier covered the region around 210 million years ago. The heat from those eruptions would have melted massive amounts of ice to form englacial lakes — bodies of water that form within glaciers like liquid bubbles in a half-frozen ice cube.

The ice-covered lakes of Arsia Mons would have held hundreds of cubic kilometers of meltwater, according to calculations by Kat Scanlon, a graduate student at Brown who led the work. And where there’s water, there’s the possibility of a habitable environment.

“This is interesting because it’s a way to get a lot of liquid water very recently on Mars,” Scanlon said.

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Meteorites Yield Clues To Red Planet’s Early Atmosphere


Geologists who analyzed 40 meteorites that fell to Earth from Mars unlocked secrets of the Martian atmosphere hidden in the chemical signatures of these ancient rocks. Their study, published April 17 in the journal Nature, shows that the atmospheres of Mars and Earth diverged in important ways very early in the 4.6 billion year evolution of our solar system.

Heather Franz, a former University of Maryland research associate who now works on the Curiosity rover science team at the NASA Goddard Space Flight Center, led the study with James Farquhar, co-author and UMD geology professor. The researchers measured the sulfur composition of 40 Mars meteorites—a much larger number than in previous analyses. Of more than 60,000 meteorites found on Earth, only 69 are believed to be pieces of rocks blasted off the Martian surface.

The meteorites are igneous rocks that formed on Mars, were ejected into space when an asteroid or comet slammed into the red planet, and landed on Earth. The oldest meteorite in the study is about 4.1 billion years old, formed when our solar system was in its infancy. The youngest are between 200 million and 500 million years old.

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Beauty From Chaos


Copyright ESA/DLR/FU Berlin

Copyright ESA/DLR/FU Berlin

Beautiful streamlined islands and narrow gorges were carved by fast-flowing water pounding through a small, plateau region near the southeastern margin of the vast Vallis Marineris canyon system.

Images captured on 7 December 2013 by ESA’s Mars Express show the central portion of Osuga Valles, which has a total length of 164 km. It is some 170 km south of Eos Chaos, which lies in the far eastern section of Valles Marineris.

Osuga Valles is an outflow channel that emanates from a region of chaotic terrain at the edge of Eos Chaos to the west (top in the main images). Such landscape is dominated by randomly oriented and heavily eroded blocks of terrain. Another example is seen at the bottom of this scene, filling the 2.5 km-deep depression into which Osuga Valles empties.

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Gusev Crater Once Held A Lake After All, Says ASU Mars Scientist


Photo by: NASA/JPL-Caltech/Cornell University/Arizona State University

Photo by: NASA/JPL-Caltech/Cornell University/Arizona State University

If desert mirages occur on Mars, “Lake Gusev” belongs among them. This come-and-go body of ancient water has come and gone more than once, at least in the eyes of Mars scientists.

Now, however, it’s finally shifting into sharper focus, thanks to a new analysis of old data by a team led by Steve Ruff, associate research professor at Arizona State University’s Mars Space Flight Facility in the School of Earth and Space Exploration. The team’s report was just published in the April 2014 issue of the journal Geology.

The story begins in early 2004, when NASA landed Spirit, one of its two Mars Exploration Rovers, inside 100-mile-wide Gusev Crater. Why Gusev? Because from orbit, Gusev, with its southern rim breached by a meandering river channel, looked as if it once held a lake – and water-deposited rocks were the rover mission’s focus. Yet, when Spirit began to explore, scientists found Gusev’s floor was paved not with lakebed sediments, but volcanic rocks.

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