Chavdarian and Sumner have studied cracks and fins in the sulfate-rich sands at White Sands National Monument in New Mexico. These features look remarkably similar to features seen by the Opportunity Mars Rover. Working at White Sands and in the lab, Chavdarian found that these features only form in sulfate sand when it is damp. The work was published earlier this year in the journal Geology.
The presence of flowing liquid water at the surface demonstrates that Mars has an active hydrologic cycle that includes significant water exchange between the subsurface and the surface, Sumner said.
“Even though liquid water is only transiently at the surface, it probably provided some water vapor to the atmosphere through evaporation and may have produced hydrous salts in surface sediments. Such hydrous sulfate salts have been inferred to be present at both MER rover sites, with the sedimentary rocks observed by Opportunity at Meridiani Planum containing more than 50% sulfates. Graduate student Greg Chavdarian and I proposed that some of the fracturing in rocks observed by Opportunity might be due to water cycling between these hydrous minerals and the atmosphere based on similar features in sulfate dunes at White Sands,” she said.
Sumner and Chavdarian have been testing their hypothesis by monitoring water cycling in the dunes at White Sands, but it has been difficult to extend their observations to match Martian conditions because of the view that the planet is so dry. But this new work suggests that a much wetter view of the planet will emerge, Sumner said.
The presence of flowing water on the surface of Mars raises many exciting possibilities for looking for life on Mars, Sumner said.
“Life does not persist in the absence of liquid water, so many astrobiologists interested in evaluating whether or not life ever existed on Mars have focused on looking for evidence of life in ancient rocks (fossil life) or have worked towards being able to drill into the subsurface of Mars to depths where liquid water may be present. Before today, we have had scant evidence that liquid water was present at depth. Now we do. And not only do we know that liquid water exists, we know that it flows to the surface, at least locally.
“The transient presence of liquid water at the surface suggests that we may not have to go into the subsurface to look for life; evidence of life or life itself might be carried to the surface by this flowing water. The water evaporates or infiltrates rapidly enough that life is unlikely to persist on the surface, but these gullies provide us with a signal from an environment within the planet that is more likely to host life than the surface.
“The presence of liquid water does not mean that life exists on Mars, but liquid water is essential for life,” Sumner said.
Andy Fell | EurekAlert!
NASA detects solar flare pulses at Sun and Earth
17.11.2017 | NASA/Goddard Space Flight Center
Pluto's hydrocarbon haze keeps dwarf planet colder than expected
16.11.2017 | University of California - Santa Cruz
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...
Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.
During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....
The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.
Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...
Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...
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15.11.2017 | Event News
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