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!
Astronomers find unexpected, dust-obscured star formation in distant galaxy
24.03.2017 | University of Massachusetts at Amherst
Gravitational wave kicks monster black hole out of galactic core
24.03.2017 | NASA/Goddard Space Flight Center
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
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