Mars contains more oxygenated water than previously thought: Study | Photo; Credit: Thinkstock;

New York: Water on Mars could hold more oxygen than previously believed, theoretically enough to support aerobic respiration, suggests a new research challenging traditional beliefs about the Red planet's habitability.

A team led by scientists from the California Institute of Technology (Caltech) and NASA's Jet Propulsion Laboratory (JPL), calculated that if liquid water exists on Mars, it could - under specific conditions - contain more oxygen than previously thought.

According to the study reported in the journal Nature Geoscience, the levels could even theoretically exceed the threshold needed to support simple aerobic life. However, the finding runs contrary to the current, accepted view of Mars and its potential for hosting habitable environments.

Researchers have long dismissed the idea that liquid water on Mars might be oxygenated, given that Mars's atmosphere is about 160 times thinner than that of Earth and is mostly carbon dioxide. "Oxygen is a key ingredient when determining the habitability of an environment, but it is relatively scarce on Mars," said Woody Fischer, a Professor at Caltech.

"Nobody ever thought that the concentrations of dissolved oxygen needed for aerobic respiration could theoretically exist on Mars," added Vlada Stamenkovic from the JPL. For the study, the team developed a chemical model describing how oxygen dissolves in salty water at temperatures below the freezing point of water.

Then, they examined the global climate of Mars and how it has changed over the past 20 million years. The team found that, at low-enough elevations (where the atmosphere is thickest) and at low-enough temperatures (where gases like oxygen have an easier time staying in a liquid solution), an unexpectedly high amount of oxygen could exist in the water - a value several orders of magnitude above the threshold needed for aerobic respiration in Earth's oceans today.

Further, the locations of those regions have shifted as the tilt of Mars's axis has changed over the past 20 million years. During that time, the highest oxygen solubilities have occurred within the past five million years.

The findings could inform future missions to Mars by providing better targets to rovers searching for signs of past or present habitable environments, Stamenkovic said.</s>If liquid water exists on Mars, it could contain more oxygen than previously thought, said a team of scientists at Caltech and joined by the Jet Propulsion Laboratory (JPL), which Caltech manages for NASA.

The levels could even theoretically exceed the threshold needed to support simple aerobic life, said scientists whose finding runs contrary to the current, accepted view of Mars and its potential for hosting habitable environments. The existence of liquid water on Mars is not a given. Even if it is there, researchers have long dismissed the idea that it might be oxygenated, given that Mars's atmosphere is about 160 times thinner than that of Earth and is mostly carbon dioxide.

"Oxygen is a key ingredient when determining the habitability of an environment, but it is relatively scarce on Mars," says Woody Fischer, professor of geobiology at Caltech and a co-author of a Nature Geoscience paper on the findings, which were published on October 22.

"Nobody ever thought that the concentrations of dissolved oxygen needed for aerobic respiration could theoretically exist on Mars," adds JPL's Vlada Stamenković, lead author of the Nature Geoscience paper.

Finding liquid water on Mars is one of the major goals of NASA's Mars program. In recent months, data from a European spacecraft have suggested that liquid water may lie beneath a layer of ice at Mars's south pole. It has also been hypothesized that water could exist in salty subsurface pools, because perchlorate salts (compounds of chlorine and oxygen) have been detected at various places on Mars.

Salt lowers the freezing point of water, which means that water with perchlorate in it could potentially stay liquid despite the freezing temperatures on Mars, where summer nights on the equator can still dip down to -100 degrees Fahrenheit.

That hypothetical salty water is what interested Fischer and Stamenković. Oxygen enters water from the atmosphere, diffusing into the liquid to maintain an equilibrium between the water and the air. If salty water were close enough to the surface of the Martian soil, then it could effectively absorb oxygen from the thin atmosphere.

To find out just how much oxygen could be absorbed, Stamenković, Fischer, and their colleagues Michael Mischna at JPL and Lewis Ward (MS '14, PhD '17) at Harvard, did two things: First, they developed a chemical model describing how oxygen dissolves in salty water at temperatures below the freezing point of water.

Second, they examined the global climate of Mars and how it has changed over the past 20 million years, during which time the tilt of the axis of the planet shifted, altering regional climates. The solubility and climate models together allowed the researchers to infer which regions on Mars are most capable of sustaining high oxygen solubilities, both today and in the planet's geologically recent past.

The team found that, at low-enough elevations (where the atmosphere is thickest) and at low-enough temperatures (where gases like oxygen have an easier time staying in a liquid solution), an unexpectedly high amount of oxygen could exist in the water—a value several orders of magnitude above the threshold needed for aerobic respiration in Earth's oceans today.

Further, the locations of those regions have shifted as the tilt of Mars's axis has changed over the past 20 million years. During that time, the highest oxygen solubilities have occurred within the past five million years.

The findings could inform future missions to Mars by providing better targets to rovers searching for signs of past or present habitable environments, Stamenković says. Their paper is titled "O2 solubility in Martian near-surface environments and implications for aerobic life."</s>A team led by scientists at California Institute of Technology (Caltech) and the Jet Propulsion Laboratory (JPL) has calculated that if liquid water exists on Mars, the planet could contain more oxygen than previously thought.

Published in the Nature journal, the study was led by researchers at NASA’s Jet Propulsion Laboratory in Pasadena. Using atmospheric models to test how oxygen might react in the water underneath the Red Planet’s surface, the team found evidence to suggest that the life-sustaining chemical element could be present to a degree higher than expected.

“Even at the limits of the uncertainties, our findings suggest that there can be near-surface environments on Mars with sufficient O2 available for aerobic microbes to breathe,” the study states.

The existence of liquid water on Mars is not a given. Even if it is there, researchers have long dismissed the idea that it might be oxygenated, given that Mars’s atmosphere is about 160 times thinner than that of Earth and is mostly carbon dioxide.

“Oxygen is a key ingredient when determining the habitability of an environment, but it is relatively scarce on Mars,” said Woody Fischer, a professor at Caltech. “Nobody ever thought that the concentrations of dissolved oxygen needed for aerobic respiration could theoretically exist on Mars,” said Vlada Stamenkovic, from JPL, lead author of the study published in the journal Nature Geoscience.</s>Atmospheric oxygen both enables complex life and is a hallmark of it. Aerobic respiration is so energetically efficient that it's thought to have been needed for multicellularity. There is hardly any oxygen in the atmosphere surrounding Mars, raising questions about the prospects for complex life there.

But it's possible some oxygen is dissolved in any watery brines that could exist at or just below the Red Planet’s surface. Geologists at CalTech and Harvard have analyzed exactly how much oxygen these brines could hold and found that it might be just enough.

A few conditions made them think there was even a chance. First, the Martian atmosphere has a tiny bit of oxygen, which is very different from it having none. (“There’s a big difference between mostly dead and all dead.”) Second, the chemistry of Martian meteorites and rocks indicates that oxygen played a role in the formation of the Martian crust. Third: the brines on or just beneath the Martian surface have a much lower freezing point than pure water because of the magnesium and calcium perchlorate salts they contain. They can supercool down to 140 to 150 Kelvin while staying liquid, and cooler liquids can dissolve more gas.

And finally: recent experiments have shown that the simplest multicellular life—microorganisms and sponges—need much less dissolved oxygen for aerobic respiration than most microbial life and simple animals do. So it would take only a minimum amount of oxygen to support something like these organisms.

So the researchers calculated the solubility of molecular oxygen in brines close to the Martian surface (since the oxygen is in equilibrium with the atmosphere) with varying levels of different salts at temperatures ranging from 140 to 300 Kelvin. They examined the brines not only of modern Mars but also Mars of 20 million years ago and 10 million years hence by noting how the conditions would change as a function of axial tilt.

Even under their worst-case estimates, the brines could hold twice as much oxygen as microbes need for aerobic respiration. At the poles, where it is colder and the brines are more likely to sporadically freeze, they could hold a million times more—enough for multicellular sponges to breathe. These oxygen levels are comparable to those in Earth’s oceans today and orders of magnitude higher than the oceans of early Earth. Comparing these results with different axial tilts over time showed that Mars has supported environments much richer in oxygen over the past five million years.

Here on Earth, photosynthesis likely put enough oxygen in the atmosphere to pave the way for aerobic respiration. But just because that’s the way aerobic life arose here doesn’t mean that’s the only way it can arise or that it has to use that route. Even though there’s only a tiny bit of oxygen in Mars’ atmosphere, this work shows that the possibility exists that there may be (or maybe once was or maybe could be) aerobic life on Mars.</s>Mars has long been thought of as dry and barren – unable to harbour life. But research over the past few years indicates that there is most likely some briny water present there today, including a possible subsurface lake.

This has led to new hopes that there could actually be life on the Red Planet after all, depending on what the conditions are like in the water.

Now, a new study, published in Nature Geoscience, surprisingly shows that brine deposits below the surface of Mars, particularly near the poles, can contain molecular oxygen – which is crucial for life on Earth.

This is exciting as it makes it even more likely that the planet could support microbial life or even simple animals like sponges.

The surface of Mars 3.8 billion to 4 billion years ago was much like Earth's and would therefore have had the right conditions for life. At that time, it had a thick atmosphere and flowing water on the surface, a global magnetic field and volcanism.

Today, the surface is dry and cold: 5 to 10 degrees Celsius (41 to 50 degrees Fahrenheit) by day and -100 to -120 degrees Celsius at night (-148 to -184 degrees Fahrenheit).

In fact, the atmospheric pressure now is less than 1 percent of Earth's, meaning that any flowing water would quickly evaporate into the atmosphere.

But it can remain trapped below the surface. Volcanism is also dead and only small-scale crustal magnetic fields remain to protect it from harsh solar radiation in the southern hemisphere.

It was for these reasons that current life on Mars was until very recently considered highly unlikely.

We now know that there are traces of methane on Mars, however, as discovered by Mars Express and the Curiosity rover.

The source of this methane might be either hydrothermal activity (the movement of heated water), or microbial life.

On Earth, flatulent cows alone produce some 25 percent to 30 percent of the methane in the atmosphere.

Either of these possibilities challenges our current understanding of the Red Planet, but if the source is life that would obviously be an amazing discovery.

The joint European and Russian ExoMars Trace Gas Orbiter is currently investigating the source of this methane.

The NASA Mars Reconnaissance Orbiter also discovered seasonal features called "recurrent slope lineae" – streak-like patterns which may indicate briny water seeping to the surface.

However there are alternative explanations. Some scientists suggest that these may also just be movements of sand.

That said, rovers and landers have found substances including calcium and magnesium perchlorates near the suspected water seeps and at other locations on Mars – and these indicate the presence of brine.

Most recently, the ESA Mars Express mission found radar evidence for liquid water underneath the south polar region on Mars – potentially a subsurface lake.

This water, which also appears to be briny, would be a whopping 20 kilometres (12 miles) wide and be situated 1.5 kilometres (1 mile) under the surface.

The new study calculated how much molecular oxygen could be dissolved in liquid brines on Mars.

It shows that the small amount of oxygen that is produced in the atmosphere could indeed become dissolved in brines at the temperature and pressure seen near the surface of Mars.

Using an atmospheric model, the researchers then studied this solubility at different locations of the planet and over time. Liquid environments which contain dissolved molecular oxygen would be scattered over most of the surface of Mars, but would be particularly concentrated near the poles where conditions are colder.

The computer models show that this could lead to breathable concentrations of oxygen for any aerobic microbes (bugs that require oxygen).

On Earth, life evolved alongside photosynthesis, which provided breathable oxygen for aerobic life.

The new results are interesting – they show how breathable oxygen could be created independently of photosynthesis. They may also explain how the oxidised rocks on the planet's surface could have formed.

So how can we find evidence of life? The current Mars missions are providing global mapping of minerals from orbit as well as information from the surface.

Recent rover results include Curiosity's discovery that organic molecules may be long lived on Mars. NASA's Mars 2020 rover mission will cache samples ready for an eventual NASA-ESA mission to return them to Earth, being planned now.

However, the NASA rovers are designed to drill only five centimetres (2 inches) under the surface.

The rover that is part of the ESA-Russia ExoMars 2020 mission that we are working on will be able to drill up to two metres (6.6 feet) below it.

This will get below where ultraviolet, cosmic and solar radiation can penetrate and harm life – providing our best hope of finding life on Mars of any planned mission.

The ExoMars rover landing site will be decided in November from two current candidates – Mawrth Vallis and Oxia Planum, both of these were ancient water-rich environments.

Although the current strategy is to search for signs of ancient life on Mars, current life should be detectable too if present.

We will have to wait for the ExoMars results to see if signs of either past or present biomarkers are present, and in the longer term analyse the returned samples.

While the rover won't go to the lake or the water seeps, there is evidence for brines at other locations too, so there is a good possibility that they may be present at the ExoMars candidate sites.

Beyond the current missions, should we be targeting the brines specifically? That certainly would provide tantalising targets for future missions.

The limit of what we can do may be imposed by the difficulty of deep drilling on a planet far away.

Drilling up to 1.5 kilometres (4,920 feet) below the surface to sample the lake would be a large scale effort beyond the capability of current technology.

The better bet may therefore be to target the nearer surface brine regions, such as the water seeps.

Another obstacle is the planetary protection rules, which state that you shouldn't risk contaminating an area where there may be extra-terrestrial life with bacteria from Earth.

However, the hope is that any Martian life would be hardy enough to populate other areas and that our missions, designed and built with strict planetary protection guidelines, will find it.

Andrew Coates, Professor of Physics, Deputy Director (Solar System) at the Mullard Space Science Laboratory, UCL.

This article is republished from The Conversation under a Creative Commons license. Read the original article.</s>Mars may be rife with dissolved oxygen in a liquid water subsurface, a team of geochemists at Caltech and NASA’s Jet Propulsion Laboratory now say.

Their findings, just published in the journal Nature Geoscience, appear to upend the long-held view that the Red Planet was largely devoid of molecular oxygen and by rote, any biological aerobic activity of the sort that might spawn life.

“This completely changes our understanding of the potential habitability of modern and old mars,” Vlada Stamenković, a JPL geochemist and the paper’s lead author, told me.

For the first time ever, says Stamenković, we’ve realized that dissolved oxygen, a molecule that was critical for the evolution of life on the Earth, could be available on Mars in quantities that could suffice to support aerobic life.

Stamenković says that their findings mean that, in theory, aerobic microbes could exist in the Martian subsurface today.

But there is still so much that we do not know about the Martian subsurface; whether there is groundwater and details about the subsurface's chemistry, says Stamenković.

Such questions won’t be resolved until there are new dedicated instruments in place to figure it all out in situ.

But Stamenkovic says that these questions about Mars’ water budget go beyond mere science .

“This is also important for the human exploration of Mars and commercial companies like SpaceX who want to go to Mars,” said Stamenković.

She says the search for extant life is tightly connected to resources such as ice, liquid water, and other volatiles – information that needs to be obtained in order to enable humans on the Red Planet.

Beyond Mars, Stamenković says the team’s results gives new hope that life can access oxygen without the need for oxygenic photosynthesis. This, she says, will be important to potentially water-rich, cooler planets, such as some planets in the TRAPPIST-1 extrasolar planetary system, which might benefit from these O2 opportunities.

Caltech reports that the team was surprised to find that on mars at low-enough elevations (where the atmosphere is thickest) and at low-enough temperatures (where gases like oxygen have an easier time staying in a liquid solution), an unexpectedly high amount of oxygen could exist in water.

Prior to this study, the assumption was that scarcity of oxygen molecules in the Martian atmosphere would also mean they were scarce throughout the subsurface. But the team’s analysis of geochemical evidence from Martian meteorites and manganese-rich rocks points to highly-oxidizing aqueous environments on Mars in its past, the authors note. This, they note, implies that O2 also played a role in the chemical weathering of the Martian crust.

This news taken in context with what geochemists know about Earth suggests that Mars may have had more oxygen than early Earth . That’s because oxygen came to become dominant on Earth only 2.35 billion years ago, or after the emergence of oxygenic photosynthesis, says Stamenković.

Thus, the surprising result is that more dissolved oxygen could exist today in Martian brines than on the early Earth, says Stamenković. That is prior to Earth’s so-called Great Oxygenation Event (GOE). This, she says, gives new hope for life on Mars and beyond for ocean worlds such as Europa and Enceladus where oxygen can be generated abiotically.

But the key to solving these questions is to design dedicated instruments to go and explore the Martian subsurface for signs of liquid water.

What’s most significant about this finding?

That oxygen might exist in sufficient quantities to support not just microbial life but also simple animals, like sponges, says Stamenković.

“There might have been different opportunities for life to emerge on Mars than on the Earth,” said Stamenković.</s>A new study, conducted by researchers led by theoretical physicist Vlada Stamenkovic, who is an Earth and planetary scientist at the Jet Propulsion Laboratory (JPL), California has found that Mars may be more hospitable to oxygen breathing life than previously thought.

The research report published in the journal Nature Geosciences revealed that the salty water near the surface of the red planet may contain a sufficient amount of dissolved oxygen to support similar microbial life that emerged and flourished billions of years ago. The study report also hinted that the amount of oxygen available in some locations could keep alive primitive multicellular organisms like sponges.

"Nobody thought of Mars as a place where aerobic respiration would work because there is so little oxygen in the atmosphere. What we're saying is it is possible that this planet that is so different from Earth could have given aerobic life a chance," said Vlada Stamenkovic, Los Angeles Times reports.

As a part of the study, Stamenkovic and his study team also identified regions of Mars with brines that contain the greatest amount of dissolved oxygen and finding such areas could help NASA as well as other space agencies to spot the right places to land during future missions.

It should be noted that pure liquid water will easily freeze in the Martian surface, but salty water in brines could remain in the liquid state at or just below the surface of the planet.

Unlike Earth's atmosphere, the surface of the red planet is not abundant with oxygen. 21 percent of the earth's atmosphere is made up of oxygen, while in Mars, the amount of oxygen is just .145 percent. The data collected by NASA Mars rovers reveal that the minuscule amount of oxygen is the result of the sun's radiation reaction with abundant carbon dioxide present in the red planet's atmosphere.

However, during the study, experts found that the oxygen concentrations on brines are especially high in brines at the polar regions. where temperatures are extremely cool.

Recently, another study published in the journal Earth and Planetary Science Letters revealed that the underground in ancient Mars had once perfect conditions to host life. The study led by Jesse Tarnas, a graduate student at Brown University revealed that ancient days in Mars had sufficient source of chemical energy required for microbes to thrive underground.</s>Eyed as prime real estate, Mars currently occupies the mind of space innovation suitors. Billions is being spent in the race to get humans to the planet but can the barren landscape be tamed? A new oxygen study provides hope.

SpaceX, Blue Origin and Boeing all have aspirations to put humans on the ground of the Red Planet. The US space agency NASA has a longstanding interest while Russia and even the United Arab Emirates each outlined their capabilities to get to, what data suggests is, a sparse, unsustainable landscape.

However, a new study into the cold, desert world could provide new impetus for explorers given that it suggests deposits of briny water may contain enough oxygen to support microbial life.

READ MORE: Is this ‘life on Mars’? New project makes walking on red planet a virtual reality (VIDEO)

Published in the Nature journal, the study was led by researchers at NASA’s Jet Propulsion Laboratory in Pasadena. Using atmospheric models to test how oxygen might react in water underneath the Red Planet’s surface, the team found evidence to suggest that the life sustaining chemical element could be present to a degree higher than expected.

“Even at the limits of the uncertainties, our findings suggest that there can be near-surface environments on Mars with sufficient O2 available for aerobic microbes to breathe,” the study states.

The study found that “high concentrations” would likely be in polar regions due to lower temperatures observed in the alien environment. “Our findings may help to explain the formation of highly oxidized phases in Martian rocks observed with Mars rovers, and imply that opportunities for aerobic life may exist on modern Mars,” the study adds.

Large bodies of water have proved elusive on Mars but over the years geological evidence obtained by NASA rovers suggest the planet was once water soaked. In 2015, NASA's Mars Reconnaissance Orbiter beamed back data showing hydrated minerals giving rise to the belief that liquid water flows intermittently on the planet.

READ MORE: Emergency escape at 6000 km/h: How near miss Soyuz rocket accident unfolded (PHOTOS, VIDEO)

Speaking about the development, the study's lead author Vlada Stamenković said the discovery could change everything.

“That's the thing of habitability; we never thought that environment could have that much oxygen. It completely changes our understanding of the potential for life on current-day Mars,” he told the National Geographic.

If you like this story, share it with a friend!</s>ALIEN LIFE: Martian water could contain enough oxygen to make it possible (Pic: GETTY)

Scientists have discovered that if water exists on Mars it could have more oxygen than ever thought possible, providing hope in the quest to find life in space.

For alien aquatic life to be present on the Red Planet, it needs to be in liquid — not frozen — water and it has to have enough oxygen.

This is tricky because Mars is very cold — plummeting to -73C in a summer night.

Although Mars can reach 20C in the summer daytime, its lack of a thick atmosphere means the nights get very cold.</s>Sponge-like creatures could be lurking beneath the surface of Mars, according to new research.

Salty subterranean lakes on the Red Planet are capable of providing enough oxygen to support even simple animals, scientists believe.

It has long believed there is not enough air on Mars to support life.

CLICK HERE FOR MORE FROM THE SUN

But a computer model developed by a US team suggests the planet's briny underground lakes is composed of salt and water.

And they are probably able to store up enough oxygen to allow alien life to flourish.

The new study, published in Nature Geoscience, believes these areas are especially concentrated in the poles of the planet.

Dr. Vlada Stamenkovic said the briny water will also be abundant in calcium and magnesium which boost bone and metabolism.

But places "with sufficient oxygen available for aerobic microbes to breathe" may be all over the Red Planet.

He added: "Moreover, about 6.5 percent of the total Martian surface area could support far higher dissolved oxygen concentrations, enabling aerobic oases sufficient to sustain the respiration demands of more complex multicellular organisms such as sponges."

It is thought that if life existed in these watery havens then they could resemble life in neighboring Earth

Dr. Stamenkovic, a planetary scientist at the California Institute of Technology in Pasadena, said: "Due to the scarcity of oxygen in the modern Martian atmosphere, Mars has been assumed to be incapable of producing environments with sufficiently large concentrations to support aerobic respiration.

"Here, we present a thermodynamic framework for the solubility of oxygen in brines under Martian near-surface conditions."

Dr. Stamenkovic said little attention has been given to the role of oxygen on Mars, due to its scarcity.

But geochemical evidence from Martian meteorites suggests it once had large amounts thanks to its warm atmosphere and liquid oceans which played a role in the weathering of its crust.

He said: "Aqueous environments, in the form of brines, can exist today at, and especially below, the surface despite the thin atmosphere and overall cold climate."

Recent evidence demonstrates hydrated magnesium and calcium salts at various locations on the surface and shallow subsurface.

This suggests there could be oxygen "comparable to the concentrations in Earth's oceans today."

Dr. Stamenkovic said: "Thus, in principle, Mars could offer a wide range of near-surface environments with enough dissolved oxygen for aerobic respiration like that seen in diverse groups of terrestrial microorganisms."

Searching alien life is something which a growing number of groups believe NASA should be doing more regularly.

For example, the National Academy of Sciences (NAS) released a report last week that calls for NASA to make the search for extraterrestrial life an "integral part of its missions."

This story originally appeared in The Sun.
A new study finds that water on Mars may contain more oxygen than previously thought.