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Water On Mars

I used to be an archaeologist once-upon-a-time, and worked on the Thames foreshore.

It don't half look like muddy silty water to me!

:shock:
 
bazizmaduno said:
see the others for that sol as the sun moves across the sky
http://marsrovers.jpl.nasa.gov/gallery/all/opportunity_p307.html

Many thanks for that link.

Having looked at all those pictures, they all seem to suggest a main pool of water (or other liquid) together with very damp surface soil with lots of surface liquid and pooling around the rock slabs. In fact, if we look towards the top left of the pictures (immediately to the left of the top, roughly rectangular, slab) we can see what appear to be 'flow patterns' in the liquid: It looks like the liquid has pooled next to the slab and that more liquid is flowing into this pool from the left. The apparent flow patterns look similar to what you'd expect on Earth due to water flowing into a silty pool: The clearer water makes little eddies and patterns as it flows into the cloudier water.

However, the 'flow patterns' do not appear to change between the pictures taken just after 09:05 and those taken just after 11:40. (They have become invisible due to shadow in the pictures taken after 16:06).

Perhaps the liquid is flowing very steadily allowing for a constant flow pattern to build up. Or perhaps the liquid (if it is a liquid) is frozen. Another thought that occurs to me is that we are looking at solid salt deposits: The evaporites left over after all the water has evaporated. In certain circumstances (perhaps due to very rapid evaporation) these could conceivably leave an appearance such as the one we are seeing here.
 
Ice lake found on the Red Planet

A giant patch of frozen water has been pictured nestled within an unnamed impact crater on Mars. The photographs were taken by the High Resolution Stereo Camera on board Mars Express, the European Space Agency probe which is exploring the planet.

The ice disc is located on Vastitas Borealis, a broad plain that covers much of Mars' far northern latitudes.

The existence of the water-ice patch on Mars raises the prospect that past or present life will one day be detected.

It also boosts the chances that manned missions could eventually be sent to the Red Planet - because they would probably need accessible water to survive.

Highly visible

The highly visible ice lake is sitting in a crater which is 35 km (23 miles) wide, with a maximum depth of about two km (1.2 miles).

Scientists believe the water-ice is present all year round because the temperature and pressure are not sufficient to allow it to change states.

Researchers studying the images are sure it is not frozen carbon dioxide (CO2), because CO2 ice had already disappeared from the north polar cap at the time the image was taken.

The team has also been able to detect faint traces of water-ice along the rim of the crater and on the crater walls.

Mars is covered with deep gorges, apparently carved out by rivers and glaciers, although most of the water vanished millions of years ago.

Earlier this year, the European Space Agency detected what they called a huge "frozen sea", but it is located below a crust of surface deposits.

Large reserves of water-ice are also known to be held at the poles on Mars, and probably at great depth at many locations around the planet.


Story from BBC NEWS:
http://news.bbc.co.uk/go/pr/fr/-/1/hi/s ... 727847.stm
Published: 2005/07/29 12:31:06 GMT

© BBC MMV
 
Martian dunes hide water secret

Scientists have found evidence that large amounts of water-ice hide within massive sand dunes on Mars.

One of the dunes, called Kaiser Dune, which spans 6.5km and rises 475m above the Martian surface, is among the largest in the Solar System.

The icy dunes could be a valuable resource for any future manned missions to the planet, said Dr Mary Bourke.

The researcher presented her results to a science conference in Dublin.

"If you're looking for a source of water for any future landers," said Dr Bourke, "I am advocating that you march up to your nearest sand dune.

"Perhaps you'll be lucky enough to find a reservoir that can be used to produce fuel and to help the survival of humans," she told the British Association's Festival of Science.

Earth parallels

The Gamma Ray Spectrometer aboard the Mars Odyssey spacecraft returned the first definitive detection of solid water on Mars in 2002.

Data from this mission allowed scientists to construct a rough map of the water content in the Martian soil. Mars' polar ice caps were found to contain up to 70% water by mass.

Dr Bourke, of the Planetary Science Institute in Arizona, US, first identified sand dunes as another possibly important reservoir of water-ice by overlaying this water content map on detailed geologic maps of Mars.

She found that the regions containing sand dunes in the planet's northern hemisphere contained perhaps 40-50% water by mass.

"It came as quite a surprise to us to realise that there could be some frozen water in these sand dunes," Dr Burke explained.

"On Earth, you do find snow and ice within sand dunes, but they're not well understood or even studied. They are reported as an oddity."

Because the resolution of the Gamma Ray Spectrometer data was not high enough to confirm the water was associated with the dunes themselves, Dr Bourke looked to more detailed satellite imagery.

Examining aerial photographs of sand dunes in Earth's polar regions allowed her to identify distinctive signatures of icy dunes which are visible from above.

Youthful features

"We were keen to identify what sand dunes look like from satellites in Antarctica," Dr Bourke explained, "because all we have for regions on Mars is satellite data."

Earth dunes containing solid water are seen to have overhanging cornices, jagged steps, and exposed ridges which result from the ice and snow binding the sand grains together and strengthening them against erosion.

That similar features are observed in the Martian dunes suggests that they, too, are strengthened by water-ice.

Even stronger evidence comes from signatures of melting, according to Dr Bourke. In regions where ice warms and seeps through the sand, dunes develop cracks and fan-shaped depressions.

Both features have been found in the Martian dunes. One fan-shaped basin seen on Mars spans over 400m, suggesting it has lost an extremely high fraction of water.

Mars' largest dune, Kaiser Dune, may contain over 500 cubic metres of water alone.

While the icy dunes on Mars cannot yet be accurately dated, the lack of cratering from asteroid impacts indicates they are relatively recent.

Dr Bourke speculates they may result from Martian snowfalls occurring in the last 100,000 years, and suggests they may eventually allow investigation of the changing Martian climate.

The dunes may also provide a new venue for the search for life on Mars, as methods have already been developed for studying biological life in similar regions on Earth.

The ability to associate water-ice with surface features as discrete, and as common, as sand dunes may be of significant practical value to any future manned mission to Mars which will need a supply of local water to survive on the planet.

http://news.bbc.co.uk/1/hi/sci/tech/4217528.stm
 
Water Detection At Gusev Described

Water Detection At Gusev Described - Chemical Proof For Two Wet Scenarios

This mini-panorama was taken by Spirit on Aug. 23, 2005, just as the rover finally completed its intrepid climb up "Husband Hill." The summit appears to be a windswept plateau of scattered rocks, little sand dunes and small exposures of outcrop.
by Tony Fitzpatrick
St Louis MO (SPX) Sep 08, 2005
A large team of NASA scientists, led by earth and planetary scientists at Washington University in St. Louis details the first solid set of evidence for water having existed on Mars at the Gusev crater, exploration site of the rover Spirit.
Using an array of sophisticated equipment on Spirit, Alian Wang, Ph.D., Washington University senior research scientist in earth and planetary sciences in Arts & Sciences, and the late Larry A. Haskin, Ph.D., Ralph E. Morrow Distinguished University Professor of earth and planetary sciences, found that the volcanic rocks at Gusev crater near Spirit's landing site were much like the olivine-rich basaltic rocks on Earth, and some of them possessed a coating rich in sulfur, bromine, chlorine and hematite, or oxidized iron.

The team examined three rocks and found their most compelling evidence in a rock named Mazatzal.

The rock evidence indicates a scenario where water froze and melted at some point in Martian history, dissolving the sulfur, chlorine and bromine elements in the soil. The small amount of acidic fluids then react with the rocks buried in the soil and formed these highly oxidized coatings.

Trench-digging rover


During its traverse from landing site to Columbia Hills, the rover Spirit dug three trenches, allowing researchers to detect relatively high levels of magnesium sulfate comprising more than 20 percent of the regolith - soil containing pieces of small rocks - within one of the trenches, the Boroughs trench. The tight correlation between magnesium and sulfur indicates an open hydrologic system - these ions had been carried by water to this site and deposited.

Spirit's fellow rover Opportunity earlier had detected a history of water at another site on Mars, Meridiani planum. This study (by Haskin et al.) covered the investigation of Spirit rover sols (a sol is a Martian day) 1 through 156, with the major discoveries occurring after sol 80.

After the findings were confirmed, Spirit traversed to the Columbian hills, where it found more evidence indicating water. The science team is currently planning for sol 551 operation of Spirit rover, which is only 55 meters away from the summit of Columbia Hills.

Spirit was on sol 597 on Sept 6 and on the summit of Husband Hill.

"We will stay on the summit for a few weeks to finish our desired investigations, then go downhill to explore the south inner basin, especially the so-called 'home-plate,' which could be a feature of older rock or a filled-in crater," Wang said. "We will name a major geo-feature in the basin after Larry."

This mini-panorama was taken by Spirit on Aug. 23, 2005, just as the rover finally completed its intrepid climb up "Husband Hill." The summit appears to be a windswept plateau of scattered rocks, little sand dunes and small exposures of outcrop.

Wang, Haskin, their WUSTL colleague Raymond E. Arvidson, chair of earth and planetary sciences, and James S. McDonnell Distinguished University Professor, and Bradley Jolliff, Ph.D., research associate professor in earth and planetary sciences, and more than two dozen collaborators from numerous institutions, reported their findings in the July 7, 2005 issue of Nature magazine (Larry A. Haskin et al. Nature 436, 66-69 (7 July 2005) doi:10.1038/nature03640).

The paper was the last one that lead author Haskin, a highly regarded NASA veteran and former chair of earth and planetary sciences at WUSTL, submitted before his death on March 24, 2005.

Buried again and again


"We looked closely at the multiple layers on top of the rock Mazatzal because it had a very different geochemistry and mineralogy," said Wang. "This told us that the rock had been buried in the soil and exposed and then buried again several times over the history. There are chemical changes during the burial times and those changes show that the soil had been involved with water.

"The telltale thing was a higher proportion of hematite in the coatings. We hadn't seen that in any previous Gusev rocks. Also, we saw very high chlorine in the coating and very high bromine levels inside the rock. The separation of the sulfur and chlorine tells us that the deposition of chlorine is affected by water."

While the multilayer coatings on rock Mazatzal indicates a temporal occurrence of low quantity water associated with freezing and melting of water, the sulfate deposition at trench sites indicates the involvement of a large body of water.

"We examined the regolith at different depths within the Big Hole and the Boroughs trenches and saw an extremely tight correlation between magnesium and sulfur, which was not observed previously," Wang said.

"This tells us that magnesium sulfate formed in these trench regoliths. The increasing bromine concentration and the separation of chlorine from sulfur also suggests the action of water. We don't know exactly how much water is combined with that. The fact that the magnesium sulfate is more than 20 percent of the examined regolith sample says that the magnesium and sulfur were carried by water to this area from another place, and then deposited as magnesium sulfate. A certain amount of water would be needed to accomplish that action."

http://www.spacedaily.com/news/mars-wat ... e-05k.html
 
More 'Icy' News...

Ice belt 'encircled Mars equator'
By Paul Rincon
BBC News science reporter, Cambridge

Europe's Mars Express probe may have found evidence for a band of ice that once spanned the Martian equator.

A frozen sea and patterns of glacial activity on the planet may be a relic of this ancient belt of ice, says a top scientist.

The ice may have formed just before five million years ago due to a change in the tilt of Mars.

This change caused moisture from the poles to be deposited as snow at the equator.

The idea is based on work by a team of scientists led by astronomer Jacques Laskar of the Paris Observatory, France.

Laskar's team has shown that the tilt of Mars on its axis can vary between 15 degrees and 40 degrees, largely because of its lack of a significant moon. By contrast, the Earth varies little from its tilt of 23.5 degrees.

Groups of modellers in Paris, Oxford and at the Nasa Ames Research Center in the US have also modelled the climatic effects of these changes in obliquity.

They found that when Mars' tilt changed to an obliquity of about 35 degrees around five million years ago, moisture trapped at the North and South Poles may have been re-deposited in equatorial regions as snow.

It is also possible that water trapped in the Martian tropics since ancient Noachian times was mobilised around five million years ago.

Eventually, the poles may have got smaller and a thick belt of ice formed around the tropics.

Now, Dr Bernard Foing, the European Space Agency's (Esa) chief scientist, said Mars Express could have found multiple lines of empirical evidence for this, including a pattern of glacial activity in the so-called tropics.

"When we look at some of the Mars Express data we find evidence of glacial deposits or even flows on the flanks of some of the equatorial mountains and volcanoes," Dr Foing told the BBC News website.

He added it was possible the ice could have got as thick as several hundred metres at high altitudes.

Evidence for recent and recurring glacial activity at tropical and mid-latitude regions on Mars has also been found by James Head of Brown University, US.

Frozen sea

Another line of evidence from Mars Express is the possible discovery of a frozen sea in the Elysium region, near the Martian equator. The finding was announced by Dr John Murray of the Open University in Milton Keynes earlier this year.

The sea, which would have been about the size of the North Sea and about 45m deep, froze as pack ice and was covered over as a layer of dust, the researchers said.

Intriguingly, the best estimate of its date comes out at about five million years, exactly when the icy belt may have existed around the tropics.

"This could be a future site for exploration, to search for possible life on Mars," said Dr Foing.

Details were announced at the American Astronomical Society's Division of Planetary Sciences meeting in Cambridge, UK.
from: http://news.bbc.co.uk/1/hi/sci/tech/4226236.stm

I didn't know about the large variability in the axial tilt, though - interesting.

Anything new about the methane detected in the atmosphere?
 
Ice Belt Encircled Mars' Equator

Study: Ice Belt Encircled Mars' Equator

2003 Hubble photo of Mars.
Cambridge, England (UPI) Sep 13, 2005
ESA's Mars Express space probe that entered orbit at the end of 2003 may have found evidence of a band of ice that once spanned the Martian equator.
Scientists says patterns of glacial activity on the planet may be a relic of an ancient belt of ice that formed about five million years ago due to a change in the tilt of Mars. That shift caused moisture from the poles to be deposited as snow at the equator.

The idea is based on work by a team of scientists led by astronomer Jacques Laskar of the Paris Observatory.

Laskar's team has shown the tilt of Mars on its axis can vary between 15 degrees and 40 degrees, largely because of its lack of a significant moon.

Researchers also found that when Mars' tilt changed to about 35 degrees, moisture trapped at the North and South Poles might have been re-deposited in equatorial regions as snow.

Eventually, the poles may have become smaller and a thick belt of ice formed around the tropics.

The study was detailed during the American Astronomical Society's Division of Planetary Sciences meeting this week in Cambridge, England.

Editor's Note: Due to a failure to correct a copy error during today's production, this report was issued with a mistake in the first paragraph where Mars Express was described as a NASA spacecraft. This is obviously not correct, and of course it should have read ESA. The chain on this error is long and goes all the way back to the original news article issued by the UPI news wire. My apologies to all concerned that this error was not picked up earlier by our editor's. SpaceDaily is very much aware that Mars Express is a flagship exploration mission for ESA, and we very much look forward to the momenteous discoveries the MARSIS radar will soon be making.

All rights reserved. © 2005 United Press International. Sections of the information displayed on this page (dispatches, photographs, logos) are protected by intellectual property rights owned by United Press International. As a consequence, you may not copy, reproduce, modify, transmit, publish, display or in any way commercially exploit any of the content of this section without the prior written consent of United Press International.

http://www.spacedaily.com/news/mars-wat ... e-05n.html
 
Simulations Show Liquid Water Could Exist on Mars



University of Arkansas researchers have become the first scientists to show that liquid water could exist for considerable times on the surface of Mars.

Image: This Petri dish contains the Mars soil stimulant used in the experiments inside the simulation chamber. Note the layers of ice and dust and the darkening of the dust. Also, water has flowed out onto the surface and in some places lies over dry soil. The mud forms a seal and helps retain water. Photos courtesy of Derek Sears.

Julie Chittenden, a graduate student with the Arkansas Center for Space and Planetary Sciences, and Derek Sears, director of the Space Center and the W.M. Keck Professor of Planetary Sciences, will report their findings in an upcoming issue of the Geophysical Research Letters.

"These experiments will help us understand how water behaves on Mars," Chittenden said.

Researchers have debated whether or not liquid water could exist on the surface of Mars because of the low temperatures and pressures found on the planet. Based on previous experiments and hypotheses, scientists have speculated that pure water on the planet's surface would evaporate from solid to gas, bypassing the liquid phase, at the low pressures found on Mars - 7 millibars as opposed to about 1,013 millibars on Earth. However, the planet's surface sports features like gullies and channels that look as though they might have been created by the movement of liquid. Terrestrial experiments designed to simulate Mars-like conditions have been performed to help answer this question of whether or not liquid water exists on Mars, but until this point they have only been done with pure water at high pressures.

Chittenden and Sears used a planetary environmental chamber in the W.M. Keck Laboratory for Space Simulation to simulate the conditions found on Mars - an atmosphere of carbon dioxide, 7 millibars of pressure and temperatures from zero degrees Celsius to 25 degrees below - and examined the evaporation rates of brine solutions expected to be found on Mars. Most water on Earth contains salts that leech into the water when it comes in contact with soil, and similar processes might be expected to occur in any surface water found on the Red Planet. Salts in the water lower the freezing point of the solution.

The University of Arkansas team placed the salt solutions in the planetary environmental chamber simulating Mars-like conditions, and then measured the evaporation rates at varying temperatures.




Image: This hydrogen distribution map from Los Alamos National Laboratories shows where hydrogen that may be tied up in water exists on Mars. Photos courtesy of Derek Sears.

"There's a huge decrease in the evaporation rate the colder it gets, more than anyone realized," Chittenden said. With the dissolved sodium and calcium in the water, the freezing point for the brine mixtures drops to 21 degrees below zero Celsius for salt water and 50 degrees below zero for water containing calcium chloride.

Temperatures on Mars vary between 125 degrees below zero Celsius and 28 degrees above at different latitudes and different times of the day. Thus, there is a possibility that liquid water could exist on the planet's surface at different locations and times of day.

"Brine formation could considerably increase the stability of water on Mars by both extending the temperature range over which liquid water is stable to negative-40 degrees Celsius and by decreasing the evaporation rates by two orders of magnitude," the researchers wrote.

Source: University of Arkansas

http://www.physorg.com/news7981.html
 
Radar reveals ice deep below Martian surface

The first ever underground investigation of another planet has been performed by a radar antenna aboard Europe's Mars Express spacecraft. The instrument probed two kilometres below the Martian surface and found tantalising hints of liquid water pooling in a buried impact crater.

The MARSIS antenna was deployed successfully in June 2005 after a series of glitches. It works by sending radio pulses towards the Red Planet and then analysing the time delay and strength of the pulses that bounce back. The radio waves that penetrate the surface rebound when they encounter a sub-surface boundary between materials with different electrical properties - such as rock and water.

But aside from one Apollo 17 radar experiment on the Moon in 1972 - which yielded mixed results - the technique had never been tested.

"This is very experimental," says William T K Johnson, MARSIS manager at NASA's Jet Propulsion Laboratory in Pasadena, California, US. "We wondered - can we see anything in the subsurface? The answer to that is yes."

Ice bowl
Johnson and colleagues have now revealed subsurface measurements of two regions in the planet's northern hemisphere – the mid-latitude lowlands called Chryse Planitia and the northern polar cap.

They believe a 250-kilometre-wide circular structure that lies between 1.5 and 2.5 kilometres below the surface of Chryse Planitia is an impact crater that was buried with volcanic ash or soil several billion years ago. The team sees no radar boundaries in material that fills the bowl of the crater and the radar signals lose no strength when passing through it. That suggests the infill must contain a large proportion of ice, which is transparent to radar.

Substantial amounts of ice in the soil would make sense given the crater's location in what appears to be a basin where ancient rivers once converged. "If the water could be captured in a basin and preserved for several billion years, it may still be there," says MARSIS co-leader Jeff Plaut of NASA's Jet Propulsion Laboratory in Pasadena, California, US.

Intriguingly, the signal reflected from the bottom of the crater is so strong and appears so flat that it may be liquid water. "If you put water there, that's what the signal might look like," Johnson told New Scientist. But he cautions the data is based on only one pass over the region and could be caused by another material.

Rare pass
MARSIS also studied the northern polar cap and found what appear to be layered deposits of nearly pure water ice stretching down 1.8 kilometres below the surface, with an icy layer of sand underneath. These layers - which include varying amounts of dust - may reveal clues about the geologic processes that shaped Mars, says Johnson: "Maybe we have a history of Mars in how thick the layers are."

The researchers are encouraged that such interesting features have emerged from only three data-gathering passes. MARSIS has only been able to make this small number of observations because the results can only be obtained under special circumstances.

It can only study the subsurface when it is closest to Mars - just 26 minutes of each 7-hour orbit – and when it is also on the planet's "night" side. That is because energetic electrons in the sunlit portions of the planet's outer atmosphere, or ionosphere, block the radar's longest, ground-penetrating wavelengths.

For the last several months, these conditions have not existed at all. But, the conditions are now right again and will remain so until May 2006. The next study regions are in the southern hemisphere, including the south pole.

But gathering the data is only the first step – it then has to be interpreted, which can take scientists months. That is because radar signals travel at different speeds through the ionosphere depending on their wavelength, and the ionosphere itself varies in size depending on the Sun's activity.

"The ionosphere is always around pestering us," says Johnson. He adds that so far the ionosphere has prevented the instrument's longest wavelengths – which could reach down as far as five kilometres - from returning data.

http://www.newscientistspace.com/article.ns?id=dn8397
 
MARSDAILY

Mars Region Probably Less Watery In Past Than Thought Says Boulder Study


A region of Mars that some planetary scientists believe was once a shallow lakebed and likely habitable for life may not have been so wet after all, according to a new University of Colorado at Boulder study.
The new study indicates chemical signatures in the bedrock, interpreted in 2004 by the Mars Exploration Rover, or MER, mission team as evidence for widespread, intermittent water at Mars' surface, may have instead been created by the reaction of sulfur-bearing steam vapors moving up through volcanic ash deposits. Known as Meridiani Planum, the region may have been more geologically similar to volcanic regions in parts of North America, Hawaii or Europe, said Thomas McCollom of CU-Boulder's Center for Astrobiology.

"Our study indicates it was probably more like parts of Yellowstone, Hawaii or Italy than something like the Great Salt Lake," said McCollom, also a research associate at CU-Boulder's Laboratory for Atmospheric and Space Physics. "We think it was far less favorable for past biological activity than other scenarios that have been proposed."

A paper on the subject by McCollom and CU-Boulder Research Associate Brian Hynek of CU-Boulder's LASP appears in the Dec. 22 issue of Nature.

A series of scientific papers published in December 2004 by the Mars Exploration Rover team and based on data gathered by the rover Opportunity, concluded that the Meridiani Planum region once probably had a large sea or huge lake that may have waxed and waned over eons. The authors proposed that the evaporation of surface and subsurface water over time left behind various chemical precipitates -- predominately sulfate salts -- which they interpreted as evidence for a watery environment that would have been conducive for life to exist.

But if the sulfate was the result of precipitation from an evaporating brine of surface and subsurface water as has been proposed, McCollom and Hynek contend the bedrock should be enriched with a large amount of positively charged atoms, known as cations, from minerals like iron, calcium and magnesium. But it is not, they said.

"We think the bedrock was laid down by enormous volcanic ash flows over time that were then permeated by sulfur dioxide-rich steam vapors," said McCollom. "The sulfur dioxide and water combined to form sulfuric acid, which reacted with and altered the bedrock to give it its present chemical composition."

The new scenario does not require prolonged interaction between bedrock and a standing body of surface water as proposed by the MER team, and the process likely occurred at high temperatures, perhaps more than 200 degrees F, said McCollom. "Everything about the site seems to be consistent with our conclusions," he said.

"In our scenario, the water required to support the chemistry in this bedrock would only have had to have been around for months, years or perhaps as much as a few centuries," said Hynek. "This is very different than previous scenarios, which require that a much larger amount of water be present for many millennia."'

The European Space Agency's Mars Express spacecraft recently showed the chemistry of layered deposits surrounding the Meridiani Planum region is similar to the bedrock at the Opportunity landing site, implying the entire area hosted volcanic activity, said Hynek. The size of the suspected Meridiani Planum volcanic deposits appears much larger than any similar deposit on Earth and encompasses an area roughly the size of Arizona, according to the CU-Boulder researchers.

McCollom described the geology of the region as "solfatara-like,"' a term that originated from Solfatara Crater, a volcanic region near Naples, Italy, harboring vents that emit vapors. "While solfataras are riddled with vents and fissures giving off sulfurous vapors at the surface, the deposits we see at Meridiani probably represent the subsurface beneath such fissures," said McCollom.

On Earth, solfataras host microbes that are capable of using sulfur for sustenance, McCollom said. Some of the areas are now under study by astrobiologists looking to characterize extreme environments on Earth that support life.

"My view is that there is a good possibility there is life on Mars, probably in the subsurface," he said. "We know from examples on Earth that life can exist in extreme places, and Mars seems to have the necessary ingredients for that."

Hynek said that in the distant past, Meridiani Planum may have had all the necessary ingredients to support organisms like those found in solfataras. "But the unique and probably short-lived nature of the environment suggests it may not be the best place to look for evidence of Martian life today," he said.

http://www.spacedaily.com/news/mars-wat ... e-05r.html
 
NASA Schedules Briefing to Announce Significant Find on Mars

WASHINGTON - NASA hosts a news briefing at 1 p.m. EST, Wednesday, Dec. 6, to present new science results from the Mars Global Surveyor. The briefing will take place in the NASA Headquarters auditorium located at 300 E Street, S.W. in Washington and carried live on NASA Television and www.nasa.gov.

The agency last week announced the spacecraft's mission may be at its end. Mars Global Surveyor has served the longest and been the most productive of any spacecraft ever sent to the red planet. Data gathered from the mission will continue to be analyzed by scientists.

Panelists include:
- Michael Meyer -- Lead Scientist, Mars Exploration Program, NASA Headquarters, Washington
- Michael Malin -- President and Chief Scientist, Malin Space Science Systems, San Diego, Calif.
- Kenneth Edgett -- Scientist, Malin Space Science Systems
- Philip Christensen -- Professor, Arizona State University, Tempe, Ariz.

Reporters at participating agency field centers will be able to ask questions. For more information about NASA TV streaming video, downlink and schedule information, visit the web at:

Here

Sounds like it could be interesting. Doubt it's going to the long awaited discovery of subsurface martian bunnies, but still could be good!

Can I be the first to declare:... "The chances of anything coming from Mars are a million to one,"

Mr P

Edit* Errr what time is 1 p.m. EST in good old UK time?
 
All I'm reading is, "We have found some tantalizing glimpses of possible life signs and or water sources, which we have been holding back and hoarding against the day when our Mars Surveyor expedition finally packs in and we have to beg for much, much more monies, which could be spent on a myriad far more serious and relevant things, from our bankrupt Government."

Sorry. Could be wrong, of course, but the hype is coming thick and fast. New Moonbases and mention of the threat of China and India getting there first and etc. all seems to be heading towards the NASA Space Collection Plate Prayathon. :(
 
1pm EST is 6pm in the Uk I beleive.

Maybe it's a probe being destroyed by a big transformer-shaped robot? :D
 
Wow!

That's got to increase the possibilities of life if it's right...
 
UsedtobChrisFord said:
Water flowing on mars. It's on their website right now.

Water maybe ...or maybe not. depending on who you ask.

Water flowed 'recently' on Mars
Nasa says it has found "compelling" evidence that liquid water flowed recently on the surface of Mars.
The finding adds further weight to the idea that Mars might harbour the right conditions for life.

The appearance of gullies, revealed in orbital images from a Nasa probe, suggests that water could have flowed on the surface in the last few years.

But some scientists think these fresh gullies could also have been cut by liquid carbon dioxide (CO2).

The latest research emerged when Nasa's Mars Global Surveyor (MGS) spacecraft spotted gullies and trenches that scientists believed were geologically young and carved by fast-moving water coursing down cliffs and steep crater walls.

Scientists at the San Diego-based Malin Space Science Systems, who operate a camera aboard MGS decided to retake photos of thousands of gullies in search of evidence for recent water activity.


We're now realising Mars is more active than we previously thought, and that the mid-latitude section seems to be where all the action is
Phil Christensen, Arizona State University

Two gullies that were originally photographed in 1999 and 2001, and imaged again in 2004 and 2005, showed changes consistent with water flowing down the crater walls, according to the study.
In both cases, scientists found bright, light-coloured deposits in the gullies that were not present in the original photos. They concluded that the deposits - possibly mud, salt or frost - were left there when water recently cascaded through the channels.

Other scientists think it possible that gullies like this were caused not by water but by liquid carbon dioxide.

One of the reasons for favouring CO2 was that computer models of the Martian crust indicated water could exist only at depths of several kilometres. Liquid carbon dioxide, on the other hand, could persist much nearer the surface where temperatures can drop as low as -107C.


Prospects for life

Oded Aharonson, an assistant professor of planetary science at the California Institute of Technology (Caltech) said that while the interpretation of recent water activity on Mars was "compelling," it was just one possible explanation.

Aharonson said further study was needed to determine whether the deposits could have been left there by the flow of dust rather than water.

Deciding what was responsible for the features is a pressing question that has important consequences for the likelihood of life on Mars. Scientists have proposed that reservoirs of liquid water could exist beneath the Martian surface, providing a habitat for microbial life.

"This underscores the importance of searching for life on Mars, either present or past," said Bruce Jakosky, an astrobiologist at the University of Colorado at Boulder, who had no role in the study. "It's one more reason to think that life could be there."

Mars Global Surveyor abruptly lost radio contact with Earth last month. Attempts to locate the spacecraft, which has mapped the Red Planet since 1996, have failed, and scientists fear it is lost.

Nasa's Mars rovers, which landed in 2004, have sent scientists back equally strong evidence that liquid water flowed on the surface in ancient times, based on observations of alterations in ancient rocks.

"We're now realising Mars is more active than we previously thought, and that the mid-latitude section seems to be where all the action is," said Arizona State University scientist Phil Christensen, who was not part of the current research.

Details of the work appear in the journal Science.

Story from BBC NEWS:
http://news.bbc.co.uk/go/pr/fr/-/1/hi/s ... 214834.stm

Published: 2006/12/06 18:13:10 GMT

© BBC MMVI
 
New Scientist version here:
http://email.newscientist.com/cgi-bin1/ ... DA0DaSi0An
(Many links on page.)
Water flows on Mars, before our very eyes
18:00 06 December 2006
NewScientist.com news service
David Shiga

This 24-metre-wide crater was first spotted in December 2003. It was not present in an earlier image from April 2001 (Image: NASA/JPL/MSSS) Liquid water has flowed on the surface of Mars within the past five years, suggest images by the now lost Mars Global Surveyor (MGS). The results appear to boost the chances that Mars could harbour life.
In 1999, MGS spotted gullies carved on the sides of Martian slopes. Thousands of gullies have been imaged since then, most recently by the Mars Reconnaissance Orbiter (MRO) (see Stunning snaps from the best camera ever sent to Mars).
Many scientists believe the gullies were carved by liquid water, although others have argued they are due to avalanches of carbon dioxide gas or rivers of dust.
The gullies appear to have formed sometime in the past several hundred thousand years, since impact craters have not accumulated on top of them. But exactly how long ago material flowed through them has not been clear.
Now, new flows have appeared in two of the gullies monitored by MGS, showing that they have been active within the past several years. The research was led by Michael Malin of Malin Space Science Systems in San Diego, California, US. That company operates the Mars Orbiter Camera on MGS, which acquired the images.
Ice shellOne gully on a crater wall that was imaged in 2001 was found to have filled with light-coloured material when it was re-imaged in 2005. A similar new light-coloured deposit appears in a 2004 image of crater gullies previously imaged in 1999.
The researchers suggest the deposits were made by liquid water flowing out from beneath the surface. The researchers estimate that each flow would have involved 5 to 10 swimming pools' worth of water.
It would have been similar to a flash flood in the desert, says team member Ken Edgett of Malin Space Science Systems. "If you were there and this thing was coming down the slope, you'd probably want to get out of the way," he says.
Any liquid water exposed to Mars's atmosphere would quickly freeze, but Malin's team says even if the exterior of the flow rapidly freezes, water could continue flowing much farther inside this ice shell, developing into a thick mixture of ice and sediment that would eventually freeze completely.
Active todayIn Mars's thin atmosphere, ice left on the surface would quickly sublimate, changing from a solid to a gas, and disappear. But water vapour diffusing out from deeper in the mixture of ice and sediment could repeatedly coat the surface with frost, maintaining its light colour long enough for MGS to spot it, the researchers say.
Alternatively, salt deposited from salty water or sediment placed there by water flow may be responsible for the light colour.
MGS team member Phil Christensen of Arizona State University in Tempe, US, who was not involved in this study, says he is convinced that the gullies were formed by the action of liquid water.
"It says something is actively going on today in at least some of these gullies and one intriguing possibility is that water was released," he told New Scientist.
"I think they make a pretty good case that these aren't simply dust avalanches or some wind-related process," he says. He adds that the sublimating carbon dioxide scenario is even less likely, because temperatures in the regions where the gullies are found – between 30° and 60° from the equator – are too high for the gas to get frozen in the first place.
Just dust?Allan Treiman of the Lunar and Planetary Institute in Houston, Texas, US, agrees that something flowed recently to make the observed changes.
But he is not convinced that water was involved. "There is no direct evidence of water in the images – only that something flowed downhill. My money is on sand and dust, because there's lots and lots of sand and dust on Mars."
Streaks on slopes have been observed before and interpreted as the result of dust avalanches. But these appear to be a separate phenomenon from the new light-coloured gully deposits, the researchers say.
Newly formed dust streaks have been observed, but are always dark. The dust streaks are also usually observed in areas where the surface clearly has a thick coating that could be dust, unlike the two craters in question. And dust streaks have never been observed on the same slopes where gullies carve into the surface.
The formation of new gullies has been observed before also, but these were on the sides of sand dunes, and were more clearly related to avalanching sand (see Landslips, impacts and eroding ice revealed on Mars).
Melting snowIf the deposits are the result of liquid water flow, the source of the water is not clear. Malin's team suggests it comes from underground aquifers, perhaps kept liquid at low temperatures with the help of high salt concentrations.
Christensen says it could result from the removal of dust from a hypothetical layer of snow, which would then melt when exposed to sunlight.
The SHARAD radar on MRO is potentially capable of detecting any underground pockets of water that the flows might have come from, Malin says. "We're hopeful that as SHARAD flies of over these locations it may be able to detect these subsurface aquifers," he says.
The new evidence that liquid water may flow on Mars today boosts the chances that life could be present, Christensen says. "I believe that we have found places on Mars where you could take terrestrial life forms that live on snow or in aquifers and put them there and they would survive," he says.
Malin's team also reports in the same study the formation on Mars of 20 new craters between 2 and 150 metres across since 1999, confirming the previously estimated rate of crater formation and reinforcing the view that crater-free areas of Mars must truly be young or recently modified.
The discovery may be one of the last from MGS, which went silent shortly before its 10th launch anniversary in early November, and has not been heard from since (see Europe joins hunt for missing Mars probe).
 
Is there not also the possibility that this gully was not seen on the earlier photos because it was covered by Mars dust?
 
Published online: 6 December 2006; |
doi:10.1038/news061204-7

Water could be flowing on Mars today
Photos show gullies growing within the past few years.
Katharine Sanderson

This gully has grown in the past few years.

NASA/JPL/MSSS

Photographs snapped of Mars show gullies that must have grown sometime in the past seven years. That, researchers say, is strong evidence that liquid water is still flowing on the red planet today. And with running water comes a better chance of finding life.

Previous work had suggested that some gullies on the planet are new in geological terms. But that could have meant anything from millions of years ago to just yesterday. The latest data, collected by the orbiting Mars Global Surveyor (MGS) before its recent demise (see 'Goodbye Mars Global Surveyor'), suggest that water flows are happening now.

"Recognizing new contemporary processes is always a thrill," says Michael Malin of instrumentation company Malin Space Science Systems in San Diego, California, who led the investigation. "The current gully activity was anticipated, but to find it actually happening was very cool."

Scientists are a long way from finding any evidence of little green bacteria on Mars, but now, they say, they have a better idea where to look. "If I were looking for life on Mars, I'd bias my research in the direction of these features," says Mike Ravine, one of Malin's colleagues.

The same project has also revealed some 20 craters that have formed since 2004. An accidental snap with MGS's wide-angled camera in January 2006 caught a black smudge of the dust kicked up by an impact. Earlier high-resolution images of this area showed no crater — in later snaps there was a small one.

Getting data about how often craters form on the surface will help scientists to date other features on Mars by looking at the cratering there. "Knowing how old bits of the surface of Mars are helps us know what Mars did when," says Albert Haldemann, Mars exploration rover scientist at the Jet Propulsion Laboratory in Pasadena, California.

Ice caps

Mars was known to hold water — but in the form of ice. There are polar ice caps on the planet, and radar signals have hinted at underground ice.

The MGS pictures, analysed by Malin and his colleagues, show gullies that look very much like they have been formed by flowing liquid — they have finger-shaped branches and travel around obstacles just as a stream on Earth would do; and there are sedimentary deposits at the ends of the tracks.

One of the gullies was snapped first in 2001, and then again in 2005. During that time, about 300 metres of new deposits had been formed. In another gully, formed sometime between 1999 and 2004 in a crater in the Centauri Montes region, a number of finger-shaped branches appeared over an area of about 600 metres.

"It really is showing we're probably getting liquid water under current climate conditions," says Nathan Bridges, who works on the High Resolution Imaging Science Experiment (HiRise), which is flying onboard the Mars Reconnaissance Orbiter.

Though there are other features on the Martian surface that seem to have been produced by flowing water — deltas at the ends of river valleys and vast flood plains — they are far, far older than the gullies seem to be.

Salty flow

There is no definite explanation yet for how the gullies are forming, or where the water might be coming from.

The gullies could be formed from snow deposits, but Malin is betting on underground water sources. His guess is that water is being heated deep within the planet's crust and bursting out to form the gullies. The question remains how the water manages to stay liquid on the chilly surface of the planet, which averages temperatures of well below zero.

"It is possible, but we don't yet have evidence, that freezing point depressants are in solution," says Malin. Salt water, for example, freezes at a lower temperature than fresh, and martian water is expected to be very briny. Pockets of the surface might also trap a lot of sunlight, heating up a small area.

These things cannot be figured out from pictures. Landing on the planet and taking samples would be the best way to work out once and for all what is happening

HiRise will set up a sort of gully watch — it has already spotted some gullies in a region very near to one of Malin's finds, and there are plans to take pictures of these every few weeks.

References
Malin M. C., Edgett K. S., Posiolova L. V., McColley S. M.& Noe Dobrea E. Z., . Science, 314 . 1573 - 1577 (2006). doi:10.1126/science.1135156


Story from [email protected]:
http://news.nature.com//news/2006/061204/061204-7.html
 
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Mars's Water Could Be Below Surface, Experts Say
Brian Handwerk
for National Geographic News

January 25, 2007
Mars may hold large underground reservoirs of the water and carbon dioxide that once formed the planet's ancient atmosphere, new research suggests.

Stas Barabash and colleagues at the Swedish Institute of Space Physics have studied the Martian atmosphere with data from the European Space Agency's Mars Express orbiter.




The team determined that, of the water and carbon dioxide that once existed on the planet, only a small amount was likely lost to the effects of solar wind over the past 3.5 billion years.

Solar wind is the flow of charged particles that flows briskly from the sun (see a virtual solar system).

Writing tomorrow's issue of the journal Science, Barabash's team suggests that water and carbon dioxide reservoirs may therefore still exist on or below the Martian surface.

Further research into the planet's subsurface and atmosphere could reveal cricitial information about Mars's climate, they add.

"Knowing [more about the ancient Martian climate], we could speculate whether or not conditions were suitable for any complex structures [like organic materials] to develop.

"The question is thus directly related to the question of Mars's habitability.

"The origin of life, in my opinion, is the most important question the modern science is facing," Barabash said.

Mystery of Missing Water

Ancient Mars was much warmer, and wetter, place than it is today. Geological features indicate that large amounts of liquid water once existed on Mars, yet no one knows what became of them.
Three main theories attempt to explain the puzzle.

Some suggest that water and carbon dioxide still exist on Mars in large reservoirs that are as yet unfound—probably below the planet's surface.


RELATED
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Photo Gallery of Mars

Other theories propose that some type of catastrophic cosmic impact removed much of the Martian atmosphere in a single event.

A third suggestion: Solar wind removed Martian water and carbon dioxide.

"I'm a plasma physicist so I really like the last one," said Barabash, a professor of experimental space physics.

"But our last study shows that escape [of water and carbon dioxide] from this channel is not as intense as we thought before, and that's a very big puzzle."

Some scientists caution that much more data is needed to make sense of the findings from Barabash's team.

"Recent measurements both from Mars Express and from Mars Global Surveyor suggest that we have not yet even described all of the loss processes at the present epoch," said Bruce Jakosky, from the Laboratory for Atmospheric and Space Physics at the University of Colorado.

"This means that we cannot yet determine the total loss rate today, let alone be able to extrapolate to earlier epochs."

Barabash also cautions that the solar wind may function in ways that scientists can't yet measure.

"It's possible that solar wind is far more complex than we think," he said. "So we have to explore other escape channels which are also associated with the solar wind."


http://news.nationalgeographic.com/news ... water.html
 
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Underground pipes channelled water on Mars

Water may have once flowed several kilometres beneath the surface of Mars in underground piping, according to new images of pipe-like fractures in bedrock taken by the most powerful camera in orbit around Mars.
Scientists have typically focused their hunt for signs of water on Mars on potential riverbeds, lakebeds and gullies. Now, these fractures could give planetary scientists a new place to look for signs of past water – and potentially life.
"These deeper underground areas may have been an oasis for any sort of biologic activity that may have been occurring," says Chris Okubo, a planetary scientist at the University of Arizona in Tucson, US.
The High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter sees long, straight dark stripes on the walls of Candor Chasma, which is part of the giant canyon system Valles Marineris.
Underground aquiferThe stripes, about half a metre wide and as long as several kilometres, are cracks in the ground that may have formed from the weight of overlying rock that has since eroded away. An alternate explanation is that the fractures may have been caused by the faulting process that formed the 4000-kilometre-long Valles Marineris canyon.
Researchers believe the cracks were already there when a liquid – most likely water from an underground aquifer – flowed through them hundreds of millions to 1 billion years ago.
Evidence for the water comes from several observations. The cracks are flanked by light bands, called halos, between 5 and 10 metres wide.
Their light colour could be explained by bleaching. Acidic water flowing along the fractures would have stripped dark iron oxide minerals from the rock, making it lighter in colour.
Water oceans?Minerals in the water may also have been deposited in the rock, cementing the grains together and making them stronger and less vulnerable to erosion. This may explain why the halos are so well preserved while the surrounding rock has eroded over millions of years.
Previous observations have also found signs of water in Candor Chasma. In 2005, the Observatoire pour la Mineralogy, l'Eau, les Glaces et l'Activité (OMEGA) hyperspectral imager onboard Europe's Mars Express spacecraft spotted calcium-rich sulphates in that area.
These sulphates form in the presence of standing water over a long period, so in addition to an underground aquifer, water may have also existed in "oceans" on the surface (see Martian water clues go wider and deeper).
Since the initial images were taken, HiRISE has spotted extensive evidence for these kinds of features in layered rock elsewhere on the planet, primarily around Mars's equator.
Cemented togetherFor instance, it has seen fluid flow features in Victoria Crater just south of the equator (see photo above), where NASA's Opportunity rover is trudging along the rim (see Mars rover snaps panorama of yawning crater). The fractures appear to be surrounded by cemented rock on the eastern crater rim and floor.
One of NASA's goals for Opportunity is to get to that side of the crater. If it is able to get close enough, Opportunity might provide some microscopic observations of the rock to confirm whether the rock has been cemented together by fluid.
Okubo says that future spacecraft, such as NASA's Mars Science Laboratory, which is expected to head to the Red Planet in 2009, could land at some of the other layered deposits to get a closer look.
Since taking these images, HiRISE has actually experienced problems with its detectors, and managers are concerned that the problem could worsen (see Mars's top camera suffers worrying glitch).

http://space.newscientist.com/article/d ... -mars.html
 
Vast ocean covered one third of surface of Mars
A vast Earth-like ocean covered a third of the surface of Mars 3.5 billion years ago, new research suggests.
Published: 7:53PM BST 13 Jun 2010

Scientists believe it stretched around the planet's northern hemisphere and held 10 times more water than all the Earth's oceans combined.

It may also have provided a cradle for the emergence of extraterrestrial life.

Scientists have long debated whether oceans, seas lakes or rivers existing on Mars long ago.

Satellite images reveal features on the planet resembling river valleys and flood plains created by flowing water. However, there are alternative explanations for their formation, such as volcanic activity.

The new research, published in the journal Nature Geoscience, provides the best evidence yet that an enormous ocean once existed on Mars.

Scientists from the University of Colorado at Boulder, US, based their findings on a study of what appear to be ancient river delta deposits and valley networks.

They identified 52 delta regions fed by numerous river-like systems. All lay at about the same height, suggesting that they marked the shoreline edge of a huge river-fed ocean.

The researchers, led by Dr Gaetano Di Achille and Professor Brian Hynek, believe the ocean covered around 36% of the planet and contained 30 million cubic miles of water.

They wrote: ''We suggest that the level reconstructed from the analysis of the deltaic deposits may represent the contact of a vast ocean covering the northern hemisphere of Mars around 3.5 billion years ago..

''Our findings lend credence to the hypothesis that an ocean formed on early Mars as part of a global and active hydrosphere.''

Another study led by Prof Hynek and reported in the Journal of Geophysical Research - Planets identified roughly 40,000 river valleys on Mars.

A key unanswered question is: where did all the water on Mars go?

Some scientists believe much of it may remain in frozen deposits underground.

River delta sediments on Earth rapidly cover up organic carbon and other biomarkers of life. For this reason, Martian delta systems are likely to be key targets for future exploration.

''On Earth, deltas and lakes are excellent collectors and preservers of signs of past life,'' said Dr Di Achille. ''If life ever arose on Mars, deltas may be the key to unlocking Mars' biological past.''

http://www.telegraph.co.uk/science/spac ... -Mars.html
 
The high seas of Mars may never have existed. According to a new study that looks at two opposite climate scenarios of early Mars, a cold and icy planet billions of years ago better explains the water drainage and erosion features seen today.

For decades, researchers have debated the climate history of Mars and how its early climate led to the many water-carved channels there now. The idea that 3 to 4 billion years ago Mars was warm, wet and Earth-like, with a northern sea—conditions that could have led to life—is generally more accepted than the concept of a frigid, icy planet where water was locked in ice most of the time and life would be hard put to evolve.

To see which early Mars model better explains the planet's modern features, Robin Wordsworth, assistant professor in environmental science and engineering at the Harvard John A. Paulson School of Engineering and Applied Sciences, and his colleagues used a 3-D atmospheric circulation model to compare a water cycle on Mars under different scenarios 3 to 4 billion years ago, during what are called the late Noachian and early Hesperian periods.

One scenario looked at Mars as a warm and wet planet with an average global temperature of 10 degrees Celsius (50 Fahrenheit), and the other as a cold and icy world with an average global temperature of minus 48 degrees Celsius (minus 54 Fahrenheit).

http://phys.org/news/2015-07-red-planet-icy-watery-billions.html
 
Long time sleeping, this thread. Probably lots of other posts that could have gone on here - like this:

Curiosity rover: The reward for 'whale watching' on Mars
Jonathan Amos Science correspondent

Whale Rock. It's got quite a story to tell.
When scientists first saw it in images returned from Nasa's Curiosity rover on Mars, they really weren't sure what to make of it.
Sitting proud on top of a stack of finely layered mudstones, this coarser sandstone seemed a little out of place.

So, the team commanded the robot to drive up and down for a bit, to look at some other enticing geology in Gale Crater.
But each time Curiosity came back for another peek, the head-scratching continued.
What was Whale Rock, and why was it there?

This week the team released its considered interpretation of the sediments observed in Gale during more than a year's roving by Curiosity.
The report, published in Science magazine, describes how these sediments are likely the remains of streams and rivers that flowed over the crater's rim and across its floor, slowing and branching into deltas that ultimately fed a succession of persistent lakes.

And Whale Rock, it turns out, has something of a starring role in this story.
"It's the rock that gives us confidence that we've got our model right," says Sanjeev Gupta, a senior scientist on the mission.

Much of what is in the Science paper was first discussed last December in a mission-team teleconference with reporters.
The intervening months have witnessed the hard graft needed to corral all the evidence into the kind of arguments that will pass muster in a peer-reviewed scholarly journal. And those arguments are compelling.

The coarser gravels that the robot saw out on the crater floor, near its landing point, gave way to progressively smaller-grained rocks as it drove south, closer to Gale's dominating central mountain, Aeolus Mons (Mount Sharp). And these dipping strata ended in a thick collection of finely layered mudstones.
The laminations are what you would expect when plume after plume of sediment pulses into a lake, loses energy and settles out of the standing water to build up the bed.

And Whale? It sits above 10m or so of these exquisite mudstones, somewhat nestled in them, and lens-shaped.
Whale has laminations, too, but its larger grains are those of a sandstone, meaning its deposition environment was more energetic. Its sediments were carried in rippling water.
All that head-scratching has concluded that Whale marks the physical edge of a lake - the interface with the delta that was feeding it.

...

For decades, researchers have wondered if the flat, northern lowlands could have held an ocean during Mars' early history. The latest Curiosity results are re-igniting interest in this idea, says John Grotzinger, the lead author on this week's paper and the former project scientist on Curiosity.

"The simplest explanation is that there probably was a body of water out there that was creating an environment at the dichotomy (the boundary between Mars' northern lowlands and southern highlands), and at Gale Crater it supplied water moisture to the northern rim that flowed into the crater basin," the Caltech professor speculated.
"Either all of these geological observations, which seem to be adding up in the same direction, are incorrect (and we always have to be open to that possibility); or we're simply missing something. Perhaps, we don't have the greenhouse gas inventory and climate conditions for early Mars correct yet.

"I don't know what we're missing but I think we're headed for a long-lived controversy in the absence of complete information."

http://www.bbc.co.uk/news/science-environment-34490337
 
This will make terraforming Mars more difficult.

There's a hole in the Martian atmosphere that opens once every two years, venting the planet's limited water supply into space — and dumping the rest of the water at the planet's poles.

That's the explanation advanced by a team of Russian and German scientists who studied the odd behavior of water on the Red Planet. Earthbound scientists can see that there's water vapor high in the Martian atmosphere, and that water is migrating to the planet's poles. But until now, there was no good explanation for how the Martian water cycle works, or why the once-drenched planet is now a dry husk.

The presence of water vapor high above Mars is puzzling because the Red Planet has a middle layer of its atmosphere that seems like it should be shutting down the water cycle altogether. [Mars-like Places on Earth]

"The Martian middle atmosphere is too cold to sustain water vapor," the researchers wrote in the study, which was published April 16 in the journal Geophysical Research Letters.

https://www.space.com/strange-martian-water-cycle.html
 
Isotopic analysis suggests there may be at least two distinct reservoirs of water beneath Mars' surface.
Mars Could Have at Least Two Ancient Reservoirs of Water Deep Underground

... (O)nce upon a time, the dry, red dustbowl of Mars was lush and soggy.

We're still unravelling the history of that water, and planetary scientists have just discovered at least two distinct reservoirs of ancient water could be preserved under the Martian surface, with different chemical signatures.

This finding indicates that, unlike Earth, Mars probably didn't have one big global ocean of underground magma encircling the entire planet.

"A lot of people have been trying to figure out Mars' water history," explained planetary scientist Jessica Barnes of the University of Arizona.

"Where did water come from? How long was it in the crust (surface) of Mars? Where did Mars' interior water come from? What can water tell us about how Mars formed and evolved?"

The evidence was found in Mars rocks. We can't exactly nip over to Mars and fetch them; indeed, to date we haven't even conducted a robotic Mars sample return mission. But occasionally, Mars comes to us anyway.

Meteorites broken off from the Martian crust will, from time to time, make their way to Earth. Here in Earth labs, using state-of-the-art techniques, researchers carefully studied two such meteorites - Allan Hills 84001, discovered in Antarctica 1984, and Northwest Africa 7034, discovered in the Sahara Desert in 2011.

The team looked at the isotopes of hydrogen locked inside the Mars rocks. Isotopes are variants of an element with different numbers of neutrons; deuterium - also known as heavy hydrogen - has one proton and one neutron. Protium, or light hydrogen, has one proton and no neutrons. ...

Here on Earth, protium is the dominant hydrogen isotope. That's true for the atmosphere (although there's not much hydrogen there), the water hydrogen in rocks, and the water in the ocean.

On Mars, deuterium is the dominant hydrogen isotope in the atmosphere, likely because solar radiation is stripping the protium - but isotope ratios in the rocks tested by scientists have run from Earth-like to Mars-like. ...

When Barnes and her team conducted their isotope analysis, they found that both samples had similar isotope ratios, sitting comfortably in between the ratio found in Earth's water and the ratio found in the Martian atmosphere. Even more peculiarly, this ratio was similar to younger rocks analysed by the Curiosity rover right there on Mars. ...

This indicates that the chemical composition of that water has been consistent for around 3.9 billion years - a completely unexpected result, given the previous research. ...

But when the team compared their results with previous research on hydrogen isotopes in meteorites from the Martian mantle - below the crust - they found something really surprising. Mantle meteorites fit into two distinct groups of igneous rock called shergottite.

Enriched shergottite has more deuterium; depleted shergottite has less deuterium. Average out their two ratios, and you get the crustal ratio seen in Allan Hills 84001 and Northwest Africa 7034.

Those two distinct chemical signatures indicate two different, unmixed reservoirs of water in the Martian mantle. Which may mean that, unlike Earth, a global ocean of liquid magma below the mantle did not homogenise the layer above. ...
FULL STORY: https://www.sciencealert.com/there-...-reservoirs-of-water-deep-underground-on-mars
 
Isotopic analysis suggests there may be at least two distinct reservoirs of water beneath Mars' surface.
FULL STORY: https://www.sciencealert.com/there-...-reservoirs-of-water-deep-underground-on-mars

See Also:
https://www.sciencedaily.com/releases/2020/03/200330110336.htm
A Martian mash up: Meteorites tell story of Mars' water history

... The researchers found that two geochemically different types of Martian volcanic rocks -enriched shergottites and depleted shergottites -- contain water with different hydrogen isotope ratios. Enriched shergottites contain more deuterium than the depleted shergottites, which are more Earth-like, they found.

"It turns out that if you mix different proportions of hydrogen from these two kinds of shergottites, you can get the crustal value," Barnes said.

She and her colleagues think that the shergottites are recording the signatures of two different hydrogen -- and by extension, water -- reservoirs within Mars. The stark difference hints to them that more than one source might have contributed water to Mars and that Mars did not have a global magma ocean.
 
Newly published research suggests Mars could have had enough water to support massive rains and floods in its very, very distant past.
Ancient Mars Had Planet-Wide Rainstorms So Intense They Breached Its Lakes

Billions of years ago, rain once fell on the Martian plain, and not always softly.

New research on the Red Planet's now-empty lakes suggests a huge amount of liquid water must have spilled from the skies roughly 3.5 to 4 billion years ago, enough to sculpt river-like channels and breach several lake basins.

"This is extremely important because 3.5 to 4 billion years ago Mars was covered with water. It had lots of rain or snowmelt to fill those channels and lakes," says planetary scientist Gaia Stucky de Quay from the University of Texas.

Modelling what Mars' climate looked like all those years ago is incredibly difficult, but studies on the geomorphology and chemistry of the planet certainly suggest it was once home to an abundance of water, fed by both rainfall and snowmelt.

Scientists aren't sure how long these downpours lasted or whether the weather was torrential, a drizzle or a mix, but marks on the surface of Mars suggest there were once heavy enough showers to leave a lasting impression. ...

FULL STORY:
https://www.sciencealert.com/a-plan...ed-several-of-its-lakes-billions-of-years-ago

PUBLISHED RESEARCH ARTICLE:

Precipitation and aridity constraints from paleolakes on early Mars
Gaia Stucky de Quay; Timothy A. Goudge; Caleb I. Fassett
Geology (2020)
https://doi.org/10.1130/G47886.1

https://pubs.geoscienceworld.org/gs...dity-constraints-from?redirectedFrom=fulltext
 
Analyses of data from prior and ongoing Mars remote sensing missions indicates there's a network of salty liquid water lakes beneath the Martian south pole.
A Network of Hidden Lakes Has Been Found Under The Surface of Mars, Scientists Say

The surface of Mars is renowned for its aridity. The entire planet is a dusty, barren desert - a wasteland of rock and, in some regions, ice; but of liquid water, not a confirmed drop has been found.

But in 2018, scientists unveiled a bombshell discovery - they'd found evidence of a colossal underground reservoir of liquid water at the Martian south pole.

Now, they've taken that discovery a crucial step forward. There's not one, but an entire network of multiple lakes under the southern polar ice cap. And that means that the first reservoir was not a one-off or a freak of Martian nature.

"The existence of a single subglacial lake could be attributed to ad-hoc conditions such as the presence of a volcano under the ice sheet, or some other situation unique to the specific location where we found the first subglacial lake," explained geophysicist Elena Pettinelli of Roma Tre University in Italy to ScienceAlert. She led the research alongside colleague Sebastian Emanuel Lauro.

"The discovery of an entire system of lakes instead, suggests their formation process to be relatively simple and possibly common." ...

Since then, the team has performed more investigations on a dataset spanning almost a decade, from 2010 and 2019. And, in a new analysis of those data, they found three new brightly reflecting patches.

In other words, a network of subglacial lakes separated by regions of dry stone, hidden away under the south pole, not far from that initial lake. ...

Moreover, if it is liquid water, it's likely salty water. Extremely salty water. ...

So the discovery of additional salty subglacial lakes is very significant. It means that they can form easily and hang around for geological timescales - which is an important piece in the longstanding puzzle of Mars' water and climate history. And it also has important implications in the search for Mars microbes. ...

"These lakes have probably existed for much of Mars' history," said planetary scientist Roberto Orosei ...

"For this reason, they could still retain traces of any life forms that could have evolved when Mars had a dense atmosphere, a milder climate and the presence of liquid water on the surface, similar to the early Earth."

It's possible, even, that microbial life may still be thriving in those lakes. ...

FULL STORY: https://www.sciencealert.com/multiple-underground-lakes-of-liquid-water-have-been-found-on-mars
 
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