NASA Confirms Strong Evidence That Liquid Water Flows on Today’s Mars

Posted on September 28, 2015


Wondering about NASA’s Mars mystery? We may have found the answer

by Alex JS, editing by Adam MS

New update from NASA news briefing:

New findings from NASA’s Mars Reconnaissance Orbiter (MRO) provide the strongest evidence yet that liquid water flows intermittently on present-day Mars.

Using an imaging spectrometer on MRO, researchers detected signatures of hydrated minerals on slopes where mysterious streaks are seen on the Red Planet. These darkish streaks appear to ebb and flow over time. They darken and appear to flow down steep slopes during warm seasons, and then fade in cooler seasons. They appear in several locations on Mars when temperatures are above minus 10 degrees Fahrenheit (minus 23 Celsius), and disappear at colder times.

“Our quest on Mars has been to ‘follow the water,’ in our search for life in the universe, and now we have convincing science that validates what we’ve long suspected,” said John Grunsfeld, astronaut and associate administrator of NASA’s Science Mission Directorate in Washington. “This is a significant development, as it appears to confirm that water — albeit briny — is flowing today on the surface of Mars.”

These downhill flows, known as recurring slope lineae (RSL), often have been described as possibly related to liquid water. The new findings of hydrated salts on the slopes point to what that relationship may be to these dark features. The hydrated salts would lower the freezing point of a liquid brine, just as salt on roads here on Earth causes ice and snow to melt more rapidly. Scientists say it’s likely a shallow subsurface flow, with enough water wicking to the surface to explain the darkening.

recurring slope lineaeThese dark, narrow, 100 meter-long streaks called recurring slope lineae flowing downhill on Mars are inferred to have been formed by contemporary flowing water. Recently, planetary scientists detected hydrated salts on these slopes at Hale crater, corroborating their original hypothesis that the streaks are indeed formed by liquid water. The blue color seen upslope of the dark streaks are thought not to be related to their formation, but instead are from the presence of the mineral pyroxene. The image is produced by draping an orthorectified (Infrared-Red-Blue/Green(IRB)) false color image (ESP_030570_1440) 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 only when the seasonal features were widest, which suggests that either the dark streaks themselves or a process that forms them is the source of the hydration. In either case, the detection of hydrated salts on these slopes means that water plays a vital role in the formation of these streaks,” said Lujendra Ojha of the Georgia Institute of Technology (Georgia Tech) in Atlanta, lead author of a report on these findings published Sept. 28 by Nature Geoscience.

Ojha first noticed these puzzling features as a University of Arizona undergraduate student in 2010, using images from the MRO’s High Resolution Imaging Science Experiment (HiRISE). HiRISE observations now have documented 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 multiple RSL locations, but only when the dark features were relatively wide. When the researchers looked at the same locations and RSL weren’t as extensive, they detected no hydrated salt.

Ojha and his co-authors interpret the spectral signatures as caused by hydrated minerals called perchlorates. The hydrated salts most consistent with the chemical signatures are likely a mixture of magnesium perchlorate, magnesium chlorate and sodium perchlorate. Some perchlorates have been shown to keep liquids from freezing even when conditions are as cold as minus 94 degrees Fahrenheit (minus 70 Celsius). On Earth, naturally produced perchlorates are concentrated in deserts, and some types of perchlorates can be used as rocket propellant.

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

Perchlorates have previously been seen on Mars. NASA’s Phoenix lander and Curiosity rover both found them in the planet’s soil, and some scientists believe that the Viking missions in the 1970s measured signatures of these salts. However, this study of RSL detected perchlorates, now in hydrated form, in different areas than those explored by the landers. This also is the first time perchlorates have been identified from orbit.

MRO has been examining Mars since 2006 with its six science instruments.

“The ability of MRO to observe for multiple Mars years with a payload able to see the fine detail of these features has enabled findings such as these: first identifying the puzzling seasonal streaks and now making a big step towards explaining what they are,” said Rich Zurek, MRO project scientist at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California.

For Ojha, the new findings are more proof that the mysterious lines he first saw darkening Martian slopes five years ago are, indeed, present-day water.

“When most people talk about water on Mars, they’re usually talking about ancient water or frozen water,” he said. “Now we know there’s more to the story. This is the first spectral detection that unambiguously supports our liquid water-formation hypotheses for RSL.”

The discovery is the latest of many breakthroughs by NASA’s Mars missions.

“It took multiple spacecraft over 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 agency’s headquarters in Washington. “It seems that the more we study Mars, the more we learn how life could be supported and where there are resources to support life in the future.”

There are eight co-authors of the Nature Geoscience paper, including Mary Beth Wilhelm at NASA’s Ames Research Center in Moffett Field, California and Georgia Tech; CRISM Principal Investigator Scott Murchie of the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland; and HiRISE Principal Investigator Alfred McEwen of the University of Arizona Lunar and Planetary Laboratory in Tucson, Arizona. Others are at Georgia Tech, the Southwest Research Institute in Boulder, Colorado, and Laboratoire de Planétologie et Géodynamique in Nantes, France.

The agency’s Jet Propulsion Laboratory (JPL) in Pasadena, California manages the Mars Reconnaissance Orbiter Project for NASA’s Science Mission Directorate, Washington. Lockheed Martin built the orbiter and collaborates with JPL to operate it.

Press released from NASA

Earlier =================

NASA says it has big news for us during a news briefing at 11:30 a.m. EDT on Monday, Sept. 28 at the James Webb Auditorium at NASA Headquarters in Washington.. “Mars Mystery Solved,” the agency’s news release touts without offering even a hint as to what mystery they mean.

For those who just can’t wait, a little Googling may solve the puzzle — and it’s not Matt Damon, little green people, or any other clear indication of life. It appears to be a confirmation of periodically flowing water on the planet’s surface.

Three of the scientists slated for the news conference are listed as authors of a new paper to be delivered at this week’s European Planetary Science Congress.

In it, the researchers say analysis of imaging from the Mars Reconnaissance Orbiter proves that seasonal dark streaks on the Martian surface are the result of briny water periodically flowing across the planet’s surface.

The confirmation of water on the surface of Mars would be important and would raise a host of questions, chief among them: Where is the water coming from, and what does it mean for the prospect of life, past or present?

The paper doesn’t answer those questions, and NASA isn’t talking ahead of its Monday morning news conference. Neither the agency nor the paper’s authors responded to requests for comment Sunday.

If Monday’s announcement isn’t about this specific paper, it’s still likely to have something to do with water: in the soil, underground or in the atmosphere. Not only is the question of water there a hot topic for research, at least two of the authors have been heavily involved in the hunt: Alfred McEwen and Lujendra Ojha.

Both were in on the initial discovery of the dark streaks back in 2011.

But whatever NASA appears ready to announce, it looks to fall short of the breathless headlines in some media outlets suggesting the NASA may have found life on the red planet, or the endless, often absurd, speculation on social media — home of the the Mars bunny, lizard, and myriad other claims based on photos sent back from the planet.

Researchers have known Mars has water for many years, based on everything from photographic evidence of structures that look like riverbeds to results of scientific experiments performed aboard landers sent to the red planet.

And some have theorized for years that dark streaks — formally called recurring slope linae — that show up on the surface when it’s warmer and fade when it’s cooler suggest the presence of flowing water. In fact Ojha suggested that very mechanism in explaining his 2011 discovery but said it could be tough to prove.

Ojha is the primary author on the new paper, in which the researchers say analysis of spectral imaging from a tool aboard the Mars Reconnaissance Orbiter proves the streaks are in fact caused by salty water flowing downhill.

The salt content of the water is important because without it, the water would freeze in Mars’ bone-chilling temperatures.

The water could be coming from subsurface ice, from salts attracting water from the thin Martian atmosphere or possibly bubbling up from an aquifer, the researchers say.

In April, McEwan announced research showing that salts in the Martian soil have the ability to grab enough water out of the air to form tiny puddles at night. And in March, NASA said Mars may once have had a sea similar to the Atlantic Ocean on Earth. About 87% of that water has been lost to space, researchers said.

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