14 ms·

NASA Rover Finds Old Streambed on Martian Surface

373 points by Sodaware 14y ago

bootload 14y ago
"... NASA's Curiosity rover mission has found evidence a stream once ran vigorously across the area on Mars where the rover is driving. There is earlier evidence for the presence of water on Mars, but this evidence -- images of rocks containing ancient streambed gravels -- is the first of its kind ..." Why isn't this front page, the implications are staggering.
- tptacek 14y ago
  Strong agree.
- tisme 14y ago
  Part of the reason may be that NASA has been crying wolf before. The 'arsenic life' announcement wasn't that long in the past. So people may be a bit wary until the images have been independently analysed.
  - bootload 14y ago
    "... So people may be a bit wary until the images have been independently analysed...." Good point. The theory of a flowing river should support all types of evidence at large & small scale: alluvial fans, "... The imagery shows an alluvial fan of material washed down from the rim, streaked by many apparent channels, sitting uphill of the new finds. ..." to pebbles and rate of flow of liquids, "... From the size of gravels it carried, we can interpret the water was moving about 3 feet per second, with a depth somewhere between ankle and hip deep... 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. ..." All directly observable evidence, each piece confirming the conclusion.
- waterlesscloud 14y ago
  I guess I'm missing the staggering implications. It's cool, and these particular rocks are fascinating, but what are the implications that are surprising? Water has always been supposed to have played a role in the state of Gale Crater, and it must have been moving water at some point...
  - shreyansj 14y ago
    The staggering implication, as someone mentioned in another reply, is that it brings us one step closer to answering whether the existence of water led to existence of lifeforms, alive or dead.
    - drgath 14y ago
      Yup. And in order for there to be flowing water on Mars, conditions had to be much much warmer on the red planet in the past. Warm enough to support Earth-like life. If life came to Earth aboard a comet (as opposed to developing here), it most likely arrived on Mars as well. In that case, the early solar system was probably teeming with life (seeds), and in that case, it could be very common elsewhere.
    - kisstheblade 14y ago
      In what way? Everything is speculation until we actually find some evidence for life. I don't understand how it helps that we prove that there were flowing rivers for example.
- InclinedPlane 14y ago
  Quite so. It means that flowing water existed in this one spot for long enough to lay down conglomerate rocks. That's a pretty damn long time. And that just strengthens the possibility of their being conditions suitable for life that much more. Also, if there was ever a significant amount of organic matter in that stream, we may be able to find out about it through the SAM instrument. It turns out someone was planning ahead and shipped a gas chromatagraph with a mass spectrometer and laser spectrometer attached. You know, just in case we wanted to pick up some dirt and figure out what the heck sort of complex chemicals are in it. Which we do!
jpxxx 14y ago
Not to burst anyone's bubble, but this is not the staggering news it's being made out to be. It is good foundational geology, yes, but water has essentially been confirmed for years now. The story of Mars in short: flop planet, can't hydrosphere. There is extremely strong evidence that in the very early years Mars was capable of holding on to a great deal of water: Enough to cover the Southern Hemisphere. The streambed seen here is from that time. That downer is that this was over 3 billion years ago. Through a variety of processes and for a number of reasons most of Mars' water was lost to space or trapped underground. The billion-dollar question that would be epic to answer: Did Mars develop Or acquire life during the time it had liquid water on the surface and if so is there any trace of it left, alive or dead?
- InclinedPlane 14y ago
  You do realize that the reason this find is significant is because it gives us more information to answer that last question, right? Especially as we drive our rover over there and study the ever loving crap out of these materials.
  - jpxxx 14y ago
    Yes, and I do realize I sound like a buzzkill - I was just trying to curb enthusiasm. "Streambed confirmed" conjures ideas of desert playas or dry gullies that are just waiting for rain, when the reality is that we're investigating a planet that hasn't seen liquid precipitation in perhaps billions of years. Condensing out all of the water currently in the Martian atmosphere would produce a layer a few microns thick. It's dry.
    - ghshephard 14y ago
      "Condensing out all of the water currently in the Martian atmosphere would produce a layer a few microns thick. It's dry." That's an interesting, and very specific number that I hadn't heard before. Is there a story behind that?
      - 14y ago
wamatt 14y ago
"From the size of gravels it carried, we can interpret the water was moving about 3 feet per second, with a depth somewhere between ankle and hip deep," said Curiosity science co-investigator William Dietrich of the University of California, Berkeley. Out of interest, how do we know it was water, and not some other liquid?
- deleted 14y ago
  [deleted]
- jpxxx 14y ago
  A good piece of evidence is that the dust of Mars is significantly composed of 'goethite', essentially hydrated iron rust. There's an awful lot of dust, and if you do the work backwards you can get a decent idea of how much water it took to make it happen. Furthermore, most liquids found at reasonable temperatures aren't all that voluminous, and a number of the minerals scanned and inspected on Mars show evidence of water contact. Basically, there's not much else it could be. :) That said there's some really cool theorizing on underground carbon dioxide flows that might explain some washouts seen later in Mars's life. http://en.wikipedia.org/wiki/Goethite http://en.wikipedia.org/wiki/Goethite
  - bootload 14y ago
    "... A good piece of evidence is that the dust of Mars is significantly composed of 'goethite' ..." you mean these? "small spherical hematite balls, dubbed ‘blueberries,’" ~ http://www.lifescientist.com.au/article/436306/iron_blueberries_may_sign_microbial_life_mars/ http://www.lifescientist.com.au/article/436306/iron_blueberr... Goethite: learn something new every day.
    - jpxxx 14y ago
      Almost! The blueberries are hematite, Fe2O3, an iron oxide. Goethite is FeO(OH), an iron oxyhydroxide. Both strongly indicate water went in to making them but the blueberries imply they were submerged in water whereas goethite doesn't necessary require anything but water vapor.
DigitalSea 14y ago
The real question is where did the water go and does it still exist somewhere on Mars? Finding a little bit of ice or water is one thing, finding an old streambed is another — but potentially finding an underwater ocean/ecosystem filled to the brim with undiscovered organisms makes me excited not only from a study of different organisms perspective but perhaps because the key to curing diseases that plague Earth might be found on Mars not to mention unlocking other discoveries like how to live longer and even more exciting finding organisms that don't age and have been alive since Mars was created. My mind is teeming with excitement of the possibilities, is anyone else as excited as me?
- MiguelHudnandez 14y ago
  Without a strong magnetic field, solar winds would blow away the atmosphere -- water vapor included. Earth has a hot, churning, iron core and therefore still has a strong magnetic field to protect our atmosphere from the solar wind. Mars cooled long ago and its magnetic field weakened.
- ChuckMcM 14y ago
  Actually if we're going to colonize Mars a large source (like Great Lakes quantity) of accessible water would solve a number of problems. So yes, that would be quite exciting. It would also be fun to discover that in its first billion years of existence as a wet planet Mars supported life in one form or another, simply to give us a data point in the probability function.
  - thaumaturgy 14y ago
    One of my favorite thought-experiments is to imagine what it would be like to have lived in a solar system that developed intelligent life on two independent planets in the same system. Imagine what that would do to culture, mythology, technological development...
- waterlesscloud 14y ago
  I almost hope no traces of life are found. If traces of life are found, however distant in the past, it seems quite likely that any Mars colony or even exploration would be delayed by decades, if not longer. Preservationists would be against any interaction whatsoever.
jpxxx 14y ago
A quick Mars timeline: Mars was formed around the time Earth was, but it was blessed with only 11% of Earth's mass and less than 40% of Earth's gravity field. Shortly after cooling solid, its "Noachian Era" was similar to proto-earth: warm, a thick atmosphere, plenty of liquid water on the surface, and probably a significant magnetic field. But this era was still during the era of the Late Heavy Bombardment, a time in which the last dregs of the solar system were still settling out. Large asteroids still pounded the planets with regularity. Unlike Earth, Mars had trouble maintaining its liquid iron magnetic field. Since it's much smaller, it cooled and thus congealed faster. And there's growing evidence that asteroid impacts were able to drive enough heat beneath the surface that interior convection was quelled, leading to a fragmented magnetic field. Without an adequate magnetic field to deflect solar wind, the atmosphere was prone to shedding off pieces of itself into space. This was amplified by the lower gravity which meant holding on to lightweight gasses was even harder. Over time, Mars cooled to the point where the major forms of tectonics ceased. The water locked up beneath the ground, rusted out pulverized basalt dust from the asteroid impacts, and frizzled in the radiation-baked atmosphere, floating off. The seas and lakes dried, the rain stopped, and that... was that. Three billion years later, we arrive on the scene and find out we have a little sibling. Then we send robots. We hope to find life, or evidence that it once lived. Characterizing how water worked in the Martian past is a part of answering that question.
- samspot 14y ago
  I really dislike when scientific theory is presented this way. You imply too much when instead of using phrasings like "We have evidence that suggest X" you say "X happened." > The seas and lakes dried, the rain stopped, and that... was that. We think there was water on mars, therefore it is true. Is it too much to put a disclaimer somewhere that explains this is the current consensus but we have more to learn? The truth is that this story is riddled with assumptions, and readers need to know that.
  - jpxxx 14y ago
    I'm not a scientist, just a pithatician. I have no formal or informal education in this matter and my understanding is strictly derived from pleasure reading. But I think there's enough evidence to back up this general narrative without throwing asterisks everywhere.
Zenst 14y ago
Out of the set of pictures I find this one the most intriging http://www.nasa.gov/mission_pages/msl/multimedia/pia16189.html http://www.nasa.gov/mission_pages/msl/multimedia/pia16189.ht... The cemented section on the mars side is in itself most interesting I find and yet seem unable to state why. Wonderous stuff indeed.
teeja 14y ago
No they didn't find a "streambed". They found a bunch of clasts, with pebbles that wind couldn't move. Perhaps they were moved by something solid rather than liquid. Perhaps that was some kind of ice. It's tiresome hearing of the "piling evidence" for water on Mars. Find some damn water. Prove it by melting it then boiling it on camera in a container with a thermometer.

373 points by Sodaware 14y ago

"... NASA's Curiosity rover mission has found evidence a stream once ran vigorously across the area on Mars where the rover is driving. There is earlier evidence for the presence of water on Mars, but this evidence -- images of rocks containing ancient streambed gravels -- is the first of its kind ..." Why isn't this front page, the implications are staggering.

tptacek 14y ago
Strong agree.
tisme 14y ago
Part of the reason may be that NASA has been crying wolf before. The 'arsenic life' announcement wasn't that long in the past. So people may be a bit wary until the images have been independently analysed.
- bootload 14y ago
  "... So people may be a bit wary until the images have been independently analysed...." Good point. The theory of a flowing river should support all types of evidence at large & small scale: alluvial fans, "... The imagery shows an alluvial fan of material washed down from the rim, streaked by many apparent channels, sitting uphill of the new finds. ..." to pebbles and rate of flow of liquids, "... From the size of gravels it carried, we can interpret the water was moving about 3 feet per second, with a depth somewhere between ankle and hip deep... 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. ..." All directly observable evidence, each piece confirming the conclusion.
waterlesscloud 14y ago
I guess I'm missing the staggering implications. It's cool, and these particular rocks are fascinating, but what are the implications that are surprising? Water has always been supposed to have played a role in the state of Gale Crater, and it must have been moving water at some point...
- shreyansj 14y ago
  The staggering implication, as someone mentioned in another reply, is that it brings us one step closer to answering whether the existence of water led to existence of lifeforms, alive or dead.
  - drgath 14y ago
    Yup. And in order for there to be flowing water on Mars, conditions had to be much much warmer on the red planet in the past. Warm enough to support Earth-like life. If life came to Earth aboard a comet (as opposed to developing here), it most likely arrived on Mars as well. In that case, the early solar system was probably teeming with life (seeds), and in that case, it could be very common elsewhere.
  - kisstheblade 14y ago
    In what way? Everything is speculation until we actually find some evidence for life. I don't understand how it helps that we prove that there were flowing rivers for example.
InclinedPlane 14y ago
Quite so. It means that flowing water existed in this one spot for long enough to lay down conglomerate rocks. That's a pretty damn long time. And that just strengthens the possibility of their being conditions suitable for life that much more. Also, if there was ever a significant amount of organic matter in that stream, we may be able to find out about it through the SAM instrument. It turns out someone was planning ahead and shipped a gas chromatagraph with a mass spectrometer and laser spectrometer attached. You know, just in case we wanted to pick up some dirt and figure out what the heck sort of complex chemicals are in it. Which we do!

jpxxx 14y ago

Not to burst anyone's bubble, but this is not the staggering news it's being made out to be. It is good foundational geology, yes, but water has essentially been confirmed for years now. The story of Mars in short: flop planet, can't hydrosphere. There is extremely strong evidence that in the very early years Mars was capable of holding on to a great deal of water: Enough to cover the Southern Hemisphere. The streambed seen here is from that time. That downer is that this was over 3 billion years ago. Through a variety of processes and for a number of reasons most of Mars' water was lost to space or trapped underground. The billion-dollar question that would be epic to answer: Did Mars develop Or acquire life during the time it had liquid water on the surface and if so is there any trace of it left, alive or dead?

InclinedPlane 14y ago
You do realize that the reason this find is significant is because it gives us more information to answer that last question, right? Especially as we drive our rover over there and study the ever loving crap out of these materials.
- jpxxx 14y ago
  Yes, and I do realize I sound like a buzzkill - I was just trying to curb enthusiasm. "Streambed confirmed" conjures ideas of desert playas or dry gullies that are just waiting for rain, when the reality is that we're investigating a planet that hasn't seen liquid precipitation in perhaps billions of years. Condensing out all of the water currently in the Martian atmosphere would produce a layer a few microns thick. It's dry.
  - ghshephard 14y ago
    "Condensing out all of the water currently in the Martian atmosphere would produce a layer a few microns thick. It's dry." That's an interesting, and very specific number that I hadn't heard before. Is there a story behind that?
    - 14y ago

wamatt 14y ago

"From the size of gravels it carried, we can interpret the water was moving about 3 feet per second, with a depth somewhere between ankle and hip deep," said Curiosity science co-investigator William Dietrich of the University of California, Berkeley. Out of interest, how do we know it was water, and not some other liquid?

deleted 14y ago
[deleted]
jpxxx 14y ago
A good piece of evidence is that the dust of Mars is significantly composed of 'goethite', essentially hydrated iron rust. There's an awful lot of dust, and if you do the work backwards you can get a decent idea of how much water it took to make it happen. Furthermore, most liquids found at reasonable temperatures aren't all that voluminous, and a number of the minerals scanned and inspected on Mars show evidence of water contact. Basically, there's not much else it could be. :) That said there's some really cool theorizing on underground carbon dioxide flows that might explain some washouts seen later in Mars's life. http://en.wikipedia.org/wiki/Goethite http://en.wikipedia.org/wiki/Goethite
- bootload 14y ago
  "... A good piece of evidence is that the dust of Mars is significantly composed of 'goethite' ..." you mean these? "small spherical hematite balls, dubbed ‘blueberries,’" ~ http://www.lifescientist.com.au/article/436306/iron_blueberries_may_sign_microbial_life_mars/ http://www.lifescientist.com.au/article/436306/iron_blueberr... Goethite: learn something new every day.
  - jpxxx 14y ago
    Almost! The blueberries are hematite, Fe2O3, an iron oxide. Goethite is FeO(OH), an iron oxyhydroxide. Both strongly indicate water went in to making them but the blueberries imply they were submerged in water whereas goethite doesn't necessary require anything but water vapor.

DigitalSea 14y ago

The real question is where did the water go and does it still exist somewhere on Mars? Finding a little bit of ice or water is one thing, finding an old streambed is another — but potentially finding an underwater ocean/ecosystem filled to the brim with undiscovered organisms makes me excited not only from a study of different organisms perspective but perhaps because the key to curing diseases that plague Earth might be found on Mars not to mention unlocking other discoveries like how to live longer and even more exciting finding organisms that don't age and have been alive since Mars was created. My mind is teeming with excitement of the possibilities, is anyone else as excited as me?

MiguelHudnandez 14y ago
Without a strong magnetic field, solar winds would blow away the atmosphere -- water vapor included. Earth has a hot, churning, iron core and therefore still has a strong magnetic field to protect our atmosphere from the solar wind. Mars cooled long ago and its magnetic field weakened.
ChuckMcM 14y ago
Actually if we're going to colonize Mars a large source (like Great Lakes quantity) of accessible water would solve a number of problems. So yes, that would be quite exciting. It would also be fun to discover that in its first billion years of existence as a wet planet Mars supported life in one form or another, simply to give us a data point in the probability function.
- thaumaturgy 14y ago
  One of my favorite thought-experiments is to imagine what it would be like to have lived in a solar system that developed intelligent life on two independent planets in the same system. Imagine what that would do to culture, mythology, technological development...
waterlesscloud 14y ago
I almost hope no traces of life are found. If traces of life are found, however distant in the past, it seems quite likely that any Mars colony or even exploration would be delayed by decades, if not longer. Preservationists would be against any interaction whatsoever.

jpxxx 14y ago

A quick Mars timeline: Mars was formed around the time Earth was, but it was blessed with only 11% of Earth's mass and less than 40% of Earth's gravity field. Shortly after cooling solid, its "Noachian Era" was similar to proto-earth: warm, a thick atmosphere, plenty of liquid water on the surface, and probably a significant magnetic field. But this era was still during the era of the Late Heavy Bombardment, a time in which the last dregs of the solar system were still settling out. Large asteroids still pounded the planets with regularity. Unlike Earth, Mars had trouble maintaining its liquid iron magnetic field. Since it's much smaller, it cooled and thus congealed faster. And there's growing evidence that asteroid impacts were able to drive enough heat beneath the surface that interior convection was quelled, leading to a fragmented magnetic field. Without an adequate magnetic field to deflect solar wind, the atmosphere was prone to shedding off pieces of itself into space. This was amplified by the lower gravity which meant holding on to lightweight gasses was even harder. Over time, Mars cooled to the point where the major forms of tectonics ceased. The water locked up beneath the ground, rusted out pulverized basalt dust from the asteroid impacts, and frizzled in the radiation-baked atmosphere, floating off. The seas and lakes dried, the rain stopped, and that... was that. Three billion years later, we arrive on the scene and find out we have a little sibling. Then we send robots. We hope to find life, or evidence that it once lived. Characterizing how water worked in the Martian past is a part of answering that question.

samspot 14y ago
I really dislike when scientific theory is presented this way. You imply too much when instead of using phrasings like "We have evidence that suggest X" you say "X happened." > The seas and lakes dried, the rain stopped, and that... was that. We think there was water on mars, therefore it is true. Is it too much to put a disclaimer somewhere that explains this is the current consensus but we have more to learn? The truth is that this story is riddled with assumptions, and readers need to know that.
- jpxxx 14y ago
  I'm not a scientist, just a pithatician. I have no formal or informal education in this matter and my understanding is strictly derived from pleasure reading. But I think there's enough evidence to back up this general narrative without throwing asterisks everywhere.

Zenst 14y ago

Out of the set of pictures I find this one the most intriging http://www.nasa.gov/mission_pages/msl/multimedia/pia16189.html http://www.nasa.gov/mission_pages/msl/multimedia/pia16189.ht... The cemented section on the mars side is in itself most interesting I find and yet seem unable to state why. Wonderous stuff indeed.

teeja 14y ago

No they didn't find a "streambed". They found a bunch of clasts, with pebbles that wind couldn't move. Perhaps they were moved by something solid rather than liquid. Perhaps that was some kind of ice. It's tiresome hearing of the "piling evidence" for water on Mars. Find some damn water. Prove it by melting it then boiling it on camera in a container with a thermometer.