{"id":16035,"date":"2015-09-28T22:34:33","date_gmt":"2015-09-28T14:34:33","guid":{"rendered":"https:\/\/wp-productionenv-bjg9h2g2bgg5b8aa.southeastasia-01.azurewebsites.net\/news\/nasa-confirms-intermittent-water-flows-on-mars\/"},"modified":"2015-09-28T22:34:33","modified_gmt":"2015-09-28T14:34:33","slug":"nasa-confirms-intermittent-water-flows-on-mars","status":"publish","type":"post","link":"https:\/\/starpath.global\/news\/nasa-confirms-intermittent-water-flows-on-mars\/","title":{"rendered":"NASA confirms intermittent water flows on Mars"},"content":{"rendered":"

STORY WRITTEN FOR CBS NEWS & USED WITH PERMISSION<\/p>\n

\"Dark,
Dark, narrow streaks on Martian slopes such as these at Hale Crater are inferred to be formed by seasonal flow of water on contemporary Mars. The streaks are roughly the length of a football field. The imaging and topographical information in this processed, false-color view come from the High Resolution Imaging Science Experiment (HiRISE) camera on NASA\u2019s Mars Reconnaissance Orbiter. Credit: NASA\/JPL-Caltech\/Univ. of Arizona<\/figcaption><\/figure>\n

Researchers using data from a NASA satellite orbiting Mars said Monday they have found clear evidence of intermittent flows of salty water on the red planet, the first \u201cunambiguous\u201d signs of liquid water on the frigid world and a possible indicator of microbe-friendly environments below the surface.<\/p>\n

\u201cMars is not the dry, arid planet we thought of in the past,\u201d Jim Green, NASA\u2019s director of planetary science, told reporters. \u201cUnder certain circumstances, liquid water has been found on Mars.\u201d<\/p>\n

The apparent flows were first noticed in 2010 by Lujendra Ojha, then an undergraduate at the University of Arizona, studying photographs taken by the Mars Reconnaissance Orbiter. Dark streaks were apparent in the sun-facing walls of steep craters near the equator during the warmer summer months.<\/p>\n

The streaks appeared to brighten and darken over the martian year, fading away during the winter and showing back up in warmer weather when the temperature climbed back above minus 10 degrees Fahrenheit. Multiple sites later were identified, in craters, cliff faces and mountainsides.<\/p>\n

Scientists came up with a variety of explanations for the branching channel-like streaks, arguing they could have been caused by some sort of surface phenomenon involving water, dust slides or other non-liquid phenomena. The water hypothesis appeared to be a stretch given the low pressure of the martian atmosphere and constant, below-freezing temperatures.<\/p>\n

But spectroscopic data from the Mars Reconnaissance Orbiter has revealed telltale signatures of hydrated salts, known as perchlorates, around numerous streaks known as \u201crecurring slope lineae,\u201d or RSLs.<\/p>\n

The hydrated minerals are consistent with magnesium perchlorate, magnesium chlorate and sodium perchlorate. Found on Earth in desert environments, perchlorates have been shown in the laboratory to keep liquids from freezing at temperatures as low as minus 94 degrees Fahrenheit.<\/p>\n

On Mars, the hydrated salts \u201cwould lower the freezing point of a liquid brine, just as salt on roads here on Earth causes ice and snow to melt more rapidly,\u201d NASA said in a statement.<\/p>\n

\"Dark
Dark narrow streaks, called \u201crecurring slope lineae,\u201d emanate from the walls of Garni Crater on Mars, in this view constructed from observations by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA\u2019s Mars Reconnaissance Orbiter. The dark streaks here are up to few hundred yards, or meters, long. They are hypothesized to be formed by flow of briny liquid water on Mars. Credit: NASA\/JPL-Caltech\/Univ. of Arizona<\/figcaption><\/figure>\n

Researchers said a sub-surface flow of briny water could allow enough liquid to \u201cwick\u201d its way to the surface to explain the recurring slope lineae. Another mechanism could be the absorption of water vapor from the thin martian atmosphere by the perchlorates, which then would dissolve away leaving a water solution behind.<\/p>\n

\u201cRegardless, the presence of hydrated salts in these flows means that these features are formed contemporary with liquid water,\u201d said Ojha, now studying for his doctorate at the Georgia Institute of Technology and lead author of a paper published Monday by Nature Geoscience.<\/p>\n

How much water? Alfred McEwen, the principal investigator for the High Resolution Imaging Science Experiment \u2014 HiRISE \u2014 aboard the Mars Reconnaissance Orbiter, said calculations based on the observed streaks indicate the global presence of more than 25 million gallons of liquid water.<\/p>\n

That \u201csounds like a lot if it\u2019s all in one place, but that\u2019s dispersed over very wide areas,\u201d he said. \u201cSo what we\u2019re dealing with is thin layers of wet soil, not standing water.\u201d<\/p>\n

Data from a variety of spacecraft have shown that Mars once hosted a warmer, wetter environment with a thicker atmosphere, flowing rivers and large bodies of water on the surface.<\/p>\n

While Mars was once habitable for life as it\u2019s known on Earth \u2014 water, organic compounds and energy from sunlight were present \u2014 it\u2019s not clear how long those conditions persisted or whether life ever had a chance to evolve. Mars today appears to be a cold, desert world.<\/p>\n

But the discovery that liquid water still flows on the red planet, even intermittently, bolsters the odds that microbial life of some sort could, in theory, still exist on Mars.<\/p>\n

\u201cWater is an essential ingredient for life,\u201d said Mary Beth Wilhelm, a researcher at NASA\u2019s Ames Research Center and the Georgia Institute of Technology. \u201cOur results may point to more habitable conditions on the near surface of Mars than previously thought.\u201d<\/p>\n

But she added that it\u2019s far from clear whether Earth-like microbes could exist in the martian environment.<\/p>\n

\u201cTo assess habitablity, we would first need to determine how cold and how concentrated the brine is,\u201d she said.<\/p>\n

But senior NASA managers were less circumspect.<\/p>\n

\u201cEverywhere we go where there\u2019s liquid water, whether its deep in the Earth or in the arid regins, we find life,\u201d Green said. \u201cWe haven\u2019t been able to answer the question \u2018does life exist beyond Earth?\u2019 But following the water is a critical element of that. We now have great opportunities to be in the right locations on Mars to thoroughly investigate that.\u201d<\/p>\n

McEwen said the discovery only strengthened his view that the probability of life on Mars is high.<\/p>\n

\u201cThere\u2019s certainly water somewhere in the crust of Mars, and Mars has received meteorites from Earth, it\u2019s been contaminated by Earth,\u201d he said. \u201cWe know that microbes can survive that trip. So it\u2019s very likely, I think, there is life somewhere in the crust of Mars, microbes. But where is it? How accessible is it? Now, maybe, there\u2019s something we can find close to the surface. That\u2019s what\u2019s exciting.\u201d<\/p>\n

Watch the news conference<\/h4>\n