New findings from NASA's Mars Reconnaissance Orbiter (MRO) give the strongest proof yet that liquid water flows discontinuously on present-day Mars.
Using an imaging spectrometer on MRO, researchers identified signatures of hydrated minerals on slopes where mysterious streaks are seen on the Red Planet. These darkish streaks seem to back and forth movement after some time. They obscure and seem to stream down steep slopes amid warm seasons, and after that blur in cooler seasons. They show up in several locations on Mars when temperatures are above minus 10 degrees Fahrenheit (minus 23 Celsius), and disappear at colder times.
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"Our quest on Mars has been to 'take after the water,' in our search for life in the universe, and now we have persuading science that validates what we've since a long time ago suspected," said John Grunsfeld, astronaut and associate administrator of NASA's Science Mission Directorate in Washington. "This is a significant advancement, as it appears to affirm that water - though briny - is streaming today on the surface of Mars."
These declining flows, known as repeating slope lineae (RSL), regularly have been described as possibly identified with liquid water. The new findings of hydrated salts on the slopes point to what that relationship may be to these dim features. The hydrated salts would bring down the point of solidification of a liquid brackish water, just as salt on roads here on Earth causes ice and snow to dissolve all the more quickly. Scientists say it's probable a shallow subsurface stream, with enough water wicking to the surface to clarify the obscuring.
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Image Credit & Copyrights: NASA Official
Dark narrow streaks called recurring slope lineae emanating out of the walls of Garni crater on Mars. The dark streaks here are up to few hundred meters in length. They are hypothesized to be formed by flow of briny liquid water on Mars. The image is produced by draping an orthorectified (RED) image (ESP_031059_1685) on a Digital Terrain Model (DTM) of the same site produced by High Resolution Imaging Science Experiment (University of Arizona). Vertical exaggeration is 1.5. |
Credits: NASA/JPL/University of Arizona
"We found the hydrated salts just when the seasonal features were widest, which suggests that either the dim streaks themselves or a process that forms them is the hydration's source. In either case, the identification of hydrated salts on these slopes means that water plays an essential part in the development of these streaks," said Lujendra Ojha of the Georgia Institute of Technology (Georgia Tech) in Atlanta, lead creator of a report on these findings published Sept. 28 by Nature Geoscience.
Ojha first saw these baffling features as a University of Arizona undergrad student in 2010, using images from the MRO's High Resolution Imaging Science Experiment (HiRISE). HiRISE observations now have recorded RSL at dozens of sites on Mars. The new study pairs HiRISE observations with mineral mapping by MRO's Compact Reconnaissance Imaging Spectrometer for Mars (CRISM).
The spectrometer observations show signatures of hydrated salts at different RSL locations, yet just when the dim features were generally wide. At the point when the researchers had a striking resemblance locations and RSL weren't as extensive, they recognized no hydrated salt.
Ojha and his co-authors translate the spectral signatures as caused by hydrated minerals called perchlorates. The hydrated salts most consistent with the compound signatures are likely a blend of magnesium perchlorate, magnesium chlorate and sodium perchlorate. Some perchlorates have been shown to keep liquids from solidifying notwithstanding when conditions are as cold as minus 94 degrees Fahrenheit (minus 70 Celsius). On Earth, normally delivered perchlorates are gathered in deserts, and some types of perchlorates can be used as rocket fuel.
Perchlorates have previously been seen on Mars. NASA's Phoenix lander and Curiosity meanderer both found them in the planet's soil, and some scientists trust that the Viking missions in the 1970s measured signatures of these salts. Be that as it may, this study of RSL recognized perchlorates, now in hydrated structure, in diverse areas than those investigated by the landers. This also is the first run through perchlorates have been distinguished from circle.
MRO has been looking at Mars since 2006 with its six science instruments.
"The capacity of MRO to observe for various Mars years with a payload ready to see the fine detail of these features has empowered findings such as these: first distinguishing the baffling seasonal streaks and now making a major step towards clarifying what they are," said Rich Zurek, MRO venture scientist at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California.
For Ojha, the new findings are more evidence that the mysterious lines he first saw obscuring Martian slopes five years back are, surely, present-day water.
"At the point when most people discuss water on Mars, they're usually discussing antiquated water or solidified water," he said. "Presently we know there's additional to the story. This is the first spectral discovery that unambiguously supports our liquid water-arrangement hypotheses for RSL."
The discovery is the latest of numerous breakthroughs by NASA's Mars missions.
"It took numerous spacecraft more than several years to solve this mystery, and now we know there is liquid water on the surface of this cold, desert planet," said Michael Meyer, lead scientist for NASA's Mars Exploration Program at the office's headquarters in Washington. "It seems that the more we study Mars, the more we figure out how life could be supported and where there are resources to support life later on."
Source: NASA.GOV
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http://www.nasa.gov/press-release/nasa-confirms-evidence-that-liquid-water-flows-on-today-s-mars
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