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Subscribe to RSSThe Mars Rover has detected the first on-the-ground evidence of an ancient streambed. If there was water, could Mars have supported life? NBC's Tom Costello reports
A close look at pebble-filled layers of rock has convinced scientists that NASA's Curiosity rover is driving through a dried-up stream bed on Mars where water flowed vigorously billions of years ago. They say it's the kind of place that just might have supported life when the planet was young.
"This is a rock that was formed in the presence of water," Caltech's John Grotzinger, project scientist for the $2.5 billion Mars Science Laboratory mission, said today during a televised news conference at NASA's Jet Propulsion Laboratory in Pasadena, Calif.
The evidence is in the shape, size and composition of the rocks that Curiosity came across at multiple sites during its landing on Aug. 5. Conglomerate rocks, consisting of pebbles cemented together within layers of sediment, were seen at three sites:
- Goulburn, a bedrock formation that was exposed by the blast from Curiosity's descent.
- Link, a rock outcrop that was seen once Curiosity headed out from the landing site.
- Hottah, an uplifted slab of craggy rock that was given a visual inspection two weeks ago.
Hottah in particular showed clear evidence of rounded pebbles that were too big to be smoothed by the action of the wind. Some of the rocks are as big as golf balls. The best explanation for the gravelly pebbles was that they were eroded by the vigorous flow of water, said Curiosity science team member Rebecca Williams, a senior scientist at the Arizona-based Planetary Science Institute.
The Hottah slab, which measures 4 to 6 inches (10 to 15 centimeters) thick, looks as if "somebody came along the surface of Mars with a jackhammer and lifted up a sidewalk that you might see in downtown LA, sort of like in a construction site," Grotzinger said.
NASA / JPL-Caltech / MSSS
A closeup view of the "Hottah" rock outcrop shows the characteristic pebbly rock that is associated with the action of a flowing stream. Broken surfaces of the outcrop have rounded, gravel clasts, such as the one circled in white, which is about 1.2 inches (3 centimeters) across. The rock formation was named after Hottah Lake in Canada's Northwest Territories.
The Planetary Science Institute's Rebecca Williams describes new images from Mars.
NASA / JPL-Caltech / MSSS / PSI
This set of images compares the Link outcrop of rocks on Mars (left) with similar rocks seen on Earth (right). The image of Link, obtained by NASA's Curiosity rover, shows rounded gravel fragments, or clasts, up to a couple of inches (few centimeters) wide, within the rock outcrop. In accordance with the Mars mission's tradition, Link takes its name from a rock formation in Canada's Northwest Territories.
The evidence from the ground meshes well with the evidence from orbit indicating that Curiosity is near an 11-mile-wide (18-kilometer-wide) fan of material that may have washed down a channel in ancient times, when Mars was warmer and wetter, according to William Dietrich, a planetary scientist at the University of California at Berkeley.
"These stones ... are very, very revealing to us about the process," Dietrich said. Some previous research has suggested that water flowed on Mars only for brief periods, separated by long, cold, dry spells. That scenario might not have provided enough time for life to get a foothold on the Red Planet in ancient times. But Dietrich said the patterning of the channels within the fan suggested that water streamed through the area for well beyond a thousand-year time scale.
"We can step away from the idea that there was a single burst of water ... that built it all in a day," he told reporters.
Based on the size of the gravel seen by Curiosity, Dietrich estimated that the water moved at a speed of about 3 feet (1 meter) per second, at a depth somewhere between ankle and hip deep.
"Plenty of papers have been written about channels on Mars with many different hypotheses about the flows in them," Dietrich said in a NASA news release. "This is the first time we're actually seeing water-transported gravel on Mars. This is a transition from speculation about the size of streambed material to direct observation of it."
NASA / JPL-Caltech / Univ. of Ariz.
This image shows the topography, with shading added, around the area where NASA's Curiosity rover landed. Higher elevations are colored in red, with cooler colors indicating transitions downslope to lower elevations. The map highlights an alluvial fan of material, apparently issuing from a channel named Peace Vallis. The black oval indicates the targeted landing area for the rover known as the "landing ellipse," and the cross shows where the rover actually landed.
NASA / JPL-Caltech / UC-Berkeley
This image shows a dry streambed on an alluvial fan in Chile's Atacama Desert, revealing the typical patchy, heterogeneous mixture of grain sizes deposited together. On Mars, Curiosity has seen two rock outcrops close to its Bradbury Landing site that also record a mixture of sand and pebbles transported by water. Scientists say the mixture was probably deposited along an ancient streambed.
So far, the scientists' conclusions are based exclusively on visual observations by Curiosity's high-resolution Mastcam imager. Further imagery, along with chemical readings from other instruments on the rover, will likely be used to fill out the story of the ancient stream bed, Grotzinger said.
The main goal of Curiosity's two-year primary mission is to assess how habitable Mars was in ancient times. That's why mission managers chose 96-mile-wide (154-kilometer-wide) Gale Crater as Curiosity's landing site. It has that alluvial fan, which appears to issue forth from a channel that has now officially been designated Peace Vallis. It also has a 3-mile-high (5-kilometer-high) mountain, known as Aeolis Mons or Mount Sharp, which could preserve billions of years' worth of Mars' geological record.
Grotzinger noted that the three requirements for habitability typically listed by astrobiologists are the presence of liquid water, the availability of an energy source (such as sunlight) and the presence of carbon-based compounds that can be used as the building blocks of life.
"Now we've got a hall pass for the water examination," Grotzinger joked.
Theoretically, a long-flowing stream could be a habitable environment. "It is not our top choice as an environment for preservation of organics, though," Grotzinger said in NASA's news release. "We're still going to Mount Sharp, but this is insurance that we have already found our first potentially habitable environment."
Even if the rover's instruments detect the right kinds of carbon compounds, that would not serve as confirmation of ancient life on Mars. That would "have to wait for another mission," Grotzinger said.
More from Mars Curiosity:
- See a crescent moon in Martian sky
- Curiosity touches first rock, then takes off
- Mars rover spots mini-moon's transit
- Cosmic Log archive on the Mars mission
Alan Boyle is NBCNews.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. To keep up with Cosmic Log as well as NBCNews.com's other stories about science and space, sign up for the Tech & Science newsletter, delivered to your email in-box every weekday. You can also check out "The Case for Pluto," my book about the dwarf planet and the search for new worlds.
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Evidence of water yes, evidence of life ending on Mars, before it was detectable in Earth, is the question.
Geoscience: Fossil raindrops and ancient air, William S. Cassata & Paul R. Renne, Nature 484,322–324(19 April 2012) doi: 10.1038/nature11036, Published online 28 March 2012
An analysis of fossil imprints of ancient raindrops suggests that the density of the atmosphere 2.7 billion years ago was much the same as that today. This result casts fresh light on a long-standing palaeoclimate paradox.
The most interesting problem is would be to find out what the composition of the Earth/Mars atmospheres during their vast history.
While the above reference determination, is more interesting in that it asks many more questions than there are answers. For example since this fossilized pattern were deposited by rain in a bed of volcanic ash, then would the critical size of the rain drops be from a rain storm induced by the volcano. Such a volcanic induced cloud burst could well have large rain drops, which as noted in the article the patterns are sensitive to.
It would see that, we should be looking, at other possibilities for determine the density of the atmosphere.
I use small thinking experiment when I am trying to open my mind to suggestion. If were to set aside 45 minutes, and attempt to imagine the Earth's history and to denote that for each second of those 45 minutes that I could think of what was happening, I would have 2,700 seconds each one summarizing a million years. Then what would I say about each of those million years? If in each single year dust accumulated or the land eroded just the thickness of sheet of paper (0.005 inches), a million years would bury or expose about 417 feet of material. In 2,700 such periods amount to 213 miles, suggesting much thinner paper! The point is that is such a long period of time, would require collecting samples, that would have very little likely hood of surviving as fossils.
But open the eyes to see that if the atmosphere Mars was once many times heavier than now, that it could have had an atmosphere with enough rain to create these billion years old water deposited samples. That the Earth once had a thicker atmosphere is scary thought, such as what happened to it, will it suffer the same fate.
Could this mean that if they perform a penetration test it could be water underneath?
Is it just me, or is NASA ripping us off on this "we think there might have been water on Mars" scam?
It's just you.
$2.5 Billion Taxpayer Dollars to tell us that there "might have been" water on Mars?
Are you under the impression that the show is now over and the credits are rolling?
Three words: It's Not Finished.
Now, after several years of operation, will MSL find something you might consider 'Earth-shaking?'
I don't know. No one does. If anyone did, we wouldn't call it research and exploration. Even Columbus died without really understanding what he'd found...
2.5 Billion is a drop in a bucket compared to what we spend in other areas. To put it in perspective, 2.5 billion is how much the military spent on gasoline...yesterday. It is also a little less than half the cost of an aircraft carrier. Learning about the nature of the Universe and potentially learning clues as to why Mars died which it is becoming increasingly evident that it appeard to be similar to Earth ought to be vastly more important than a great many other things that our government pours our money into.
Well, the waters gone gone now. So who cares. We have destroyed the water quality in every place we could on the earth. We have put PCB's ,pesticides, herbicides,fungicides a lot of agro chemicals in all the streams rivers, ponds, lakes of every state not to mention the methy mercury all over the world and its oceans due to the coal. Theres no way to clean it up either. The damage has been done. Now we have affected the fish and wildlife as well as the drinking water by these chemicals. It will take over 500 million years before we have a habitable planet to live on again. But humans will be long gone by then. Why spend $billions on trying to travel to mars? Everyday we have hundreds of thousands of people lacking food and millions more without any health care, and we spend trillions on war weapons. The worlds countries aborts millions of human beings each month. The world seems to hate itself and it is so filled with rage and anger that it is preoccupied with ensuring it can destroy its enemies real and perceived. There is little hope for the human race. The time when a nuclear weapon is used in anger or by miscalculation or by madness is quickly approaching. Where it will be used and what city is going to be targeted is anybodys guess. It is certain to destroy the worlds economy and bring all the worlds leaders to the table to prepare treaties and agreements to supervise the stockpiles and manufacture of bomb making fissionable material. If the world is "lucky" it will only be one weapon used and not an exchange between the US and Russia or China. Or between Pakistan and India, or between North Korea and South Korea. The US has almost been destroyed two times already. The US was within hours of launching our attack on Russia in 1962. Then again in 1983 when the Soviets were convined the US was going to do a first strike upon the Soviets partly due to Reagans Adolescent ramblings about Russia being declared evil. There cannot be a limited nuclear exchange. Whether its the US and Russia or the US and China or Pakistan and India. It will be total war.
Sir, once again, I care. The rest of that wall of text is a red herring!
Good evening Thanatocoenosis,
We must not be too hard on "John" without knowing the full story here. I suspect "he" is simply putting into HIS words the following, in summary.
"In the event that I am reincarnated,, I would like to return as a deadly virus, in order to contribute something to solve overpopulation."
Prince Phillip, Husband of Queen Elizabeth, in 1988
(In all honesty , that IS the reason we, by necessity, are "Reaching to the stars ," as the good Professor /Astrophysicist Stephen Hawking calls it. Along with an "accident", which he also refers to, so..)
:-)
Why do they assume it was water? Is water the only liquid that can flow? Couldn't those channels have been made by some other liquid elemental mixture? Occam's Razor, always assume the simplest solution, it's usually correct? Is it because of the atmosphere? Or am I just sounding dum?
There's also chemistry and physics. There aren't many other substances that:
1. Physically could have been liquid, even for a relatively short time under the conditions on Mars, either as they are currently, or or in a probable warmer, denser atmosphered past...
2. And are also made of common elements in the solar system and universe as a whole.
(When you have lots of elements like hydrogen, oxygen, nitrogen and carbon present, it's reasonable to expect the combinations of those that give you water, methane (and a few longer chain hydrocarbons) ammonia and carbon dioxide. But Mars isn't cold enough [or have enough atmospheric pressure, in the case of CO2] for the last three to exist as liquid. Even less so, in the case of liquid molecular nitrogen, oxygen, or hydrogen.
Isaac Asimov once wrote an essay called 'Recipe for an Ocean,' wherein he discusses the possible liquids planetary oceans could possibly be made of, and quickly excluded things like oceans of liquid gold on hot planets...because gold [and most other elements] is not sufficiently common in the Universe for a planet to possess enough to collect into a body worthy of being called an ocean. Methane is made of some pretty common stuff [carbon and hydrogen], we see it as gases in some planetary atmospheres, and Titan has shown us that very large lakes of the stuff can exist under the much colder conditions there. Indeed, it can exist as solid, liquid or gas on Titan, just as water can on Earth. Solid and gaseous carbon dioxide exists on Mars, but the pressure there [or even here] is much too low for liquid CO2. Indeed, even water would freeze or evaporate very quickly on Mars...at least today.)
So, as Sherlock Holmes said, when you have eliminated the impossible...
And yes, though Occam's Razor is not a law of physics, it's a powerful logical tool.
The question is where did all of the water goto?
Could it be possible that there was an enormous mars quake that caused the water to be redirected to underground streams?
Lets hope so.
I am not sure, but I believe the theory is that as the Martian atmosphere was worn away by the solar wind (following a significant decline in the strength of Mars' magnetic field), conditions at the surface no longer were sufficient for liquid water. Water either became solid or vaporous. The vapors probably drifted off with the lost atmosphere, with the solid either remaining behind (ice at Martian poles) or melting, turning into vapor and dissolving. I'm no expert, and not that well versed in chemistry, but I think that is about what has been suggested.
I certainly hope that if man ever finds a habitable planet to start over, he has learned his lessons on THIS planet in regard to overpopulation, wars, etc. and therefore will, from day one make:
SEWN UP FOOTED PAJAMAS the mandated uniform/apparel for all, in order to preclude the above in the future.
Jesusniggeringchrist! The science ignorant phuqtards... my head explodeds! America iz doomed!
Whoa... cool script... substituting "j. e. s. u. s" with "@!$%#"... Phuqtard rascist.
Keep it up Alan. I was on the multimedia site last night and one of those mars pics was not there!!....I have been keenly looking at these pics as they come in and figured, as some posters have mentioned, this would be agreat place to find small fossils!!!....I do not yet see anything that says fossil, but there are plenty of canidates!!...one thing I would ask of the rover team, take a pic...xmit it, wait a few minutes, take exactly the same pic again!! a set of pics like that could keep me busy for a few days!!!......I am working an alternate theory that at night gases condensate and gravity is doing the rest, ie, the streams are functioning STREAMS, RIGHT NOW!!....I don't believe that, but I am not convinced that small impulses of barely liquid gasses flowing in volumes of nano liters per second, multiplied by forever, is equal to a great river flowing for a few thousand years. I am betting we find fossils sooner than we expect. Probably have overlooked several already, since it is our nature to look for things as we know them to be, not what reality so often shows us. Man, we need an RTG powered robot on the moon, like yesterday!!!....if nuclear chicago puts one on the moon to look for and gather x (no not oil)..then it's ALL our faults.
How many think the first martian fossil found will be: Sqaure? Triangular? Round? Tubular? Hexagonal? Other? Non-existant?
Keep it up Alan. I was on the multimedia site last night and one of those mars pics was not there!!....I have been keenly looking at these pics as they come in and figured, as some posters have mentioned, this would be agreat place to find small fossils!!!....I do not yet see anything that says fossil, but there are plenty of canidates!!...one thing I would ask of the rover team, take a pic...xmit it, wait a few minutes, take exactly the same pic again!! a set of pics like that could keep me busy for a few days!!!......I am working an alternate theory that at night gases condensate and gravity is doing the rest, ie, the streams are functioning STREAMS, RIGHT NOW!!....I don't believe that, but I am not convinced that small impulses of barely liquid gasses flowing in volumes of nano liters per second, multiplied by forever, is equal to a great river flowing for a few thousand years. I am betting we find fossils sooner than we expect. Probably have overlooked several already, since it is our nature to look for things as we know them to be, not what reality so often shows us. Man, we need an RTG powered robot on the moon, like yesterday!!!....if nuclear chicago puts one on the moon to look for and gather x (no not oil)..then it's ALL our faults.
How many think the first martian fossil found will be: Sqaure? Triangular? Round? Tubular? Hexagonal? Other? Non-existant?
darned newsvine, making us users look like we can't click a darned post button
Interesting article and comments
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