Did Mars Once Have Flowing Water?

  • Context: High School 
  • Thread starter Thread starter shifty88
  • Start date Start date
  • Tags Tags
    Mars Proof
Click For Summary

Discussion Overview

The discussion centers around the question of whether Mars once had flowing water and the implications of this for understanding its hydrological cycle. Participants explore various aspects of this topic, including evidence for past water flow, the nature of Martian hydrology, and comparisons to Earth's water cycle.

Discussion Character

  • Exploratory
  • Debate/contested
  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • Some participants reference articles suggesting evidence of running water on Mars, proposing that this indicates a past hydrological cycle similar to Earth's.
  • Others challenge the assertion that the presence of water equates to a hydrological cycle, arguing that running water does not necessarily imply an Earth-like system.
  • One participant suggests that running water could occur without a hydrological cycle, proposing scenarios such as meteor impacts causing temporary water flow.
  • There is a discussion about the nature of Martian hydrology, with some arguing that while Mars has a water cycle, it is not analogous to Earth's, involving processes like vaporization and atmospheric transport.
  • Participants debate the role of geological processes, such as lava flows, in shaping the Martian landscape and whether they could mimic the effects of water erosion.
  • Some express disappointment over the lack of thorough investigation into Martian riverbeds and the implications of such findings for understanding past life on Mars.
  • One participant argues that if water flows downhill, it implies some form of hydrological cycle, though they acknowledge it may not be Earth-like.

Areas of Agreement / Disagreement

Participants do not reach a consensus on whether Mars had an Earth-like hydrological cycle. There are multiple competing views regarding the implications of evidence for running water and the nature of Martian hydrology.

Contextual Notes

Some claims depend on interpretations of geological evidence and the definitions of hydrological processes, which remain unresolved in the discussion.

Astronomy news on Phys.org


shifty88 said:
Interesting article about proof of running water on the surface of Mars. This means that Mars once had a hydrologic cycle similar to what we see on earth.
Leaving aside whether or not there is evidence of this these two statements are missing a cogent argument to support a link between them.

Presence of water is not evidence for a past hydrological cycle.
 


running water itself is evidence of hydrology in itself.
 
shifty88 said:
running water itself is evidence of hydrology in itself.
Forgive the pun but that's a world away from an Earth like hydrological cycle
 


what are some things that could cause running water with no hydrological cycle?

Maybe a meteor hitting the ice cap...?

I mean, since they determined that there was running water because of the fact that the rocks appear to have been smoothed by water and carried in a stream, doesn't that mean that the water must have been flowing for a relatively long time?
 


SHISHKABOB said:
what are some things that could cause running water with no hydrological cycle?

Maybe a meteor hitting the ice cap...?

I mean, since they determined that there was running water because of the fact that the rocks appear to have been smoothed by water and carried in a stream, doesn't that mean that the water must have been flowing for a relatively long time?
Simplistically the hydrological cycle involves storage in oceans/land, evaporation into the atmosphere, precipitation and run off back to sites where it can begin the cycle again. There's no evidence that this happens on Mars and running water itself is not indicative of an Earth like cycle which was what the OP asserted.

As for why water would run on Mars I'm no expert but perhaps freeze/thaw cycles that modify the landscape until stored water begins to run from one place to another. Hardly the same.
 


Seems like the logical conclusion; after all there's lots of orbital photographs with evidence of running water on Mars. I don't have to tell you that water pools at the lowest point, and that water must of been going somewhere for sometime to erode bedrock like that, there must had been some sort of 'resupply'.

Why would the cycle be different on another planet. Titan has liquid lakes of methane and methane rainfall. Not a hydrological process I know; but the process is the same. perhaps suggesting some kind of natural process, why would you assume the natural process' ends 50 miles up.
 


Correct me if I am wrong, but don't lava flows erod rock like flowing water too?
 


my two cents:

Mars _does_ have a water cycle albeit *not* earthlike. What happens is that the polar cap, does not just melt, it vaporizes, releasing carbon dioxide and water vapor in the summer hemisphere, and that results in highspeed winds. this wind drives dust, and ice crystals and water vapor and anything in its way to the other hemisphere, where it mixes with the atmosphere there.

in the winter hemisphere, up to 40% of the atmospheric volume is frozen in CO2 polar caps.

water clouds and rain ALSO seen in mars, but that water binds itself with permafrost.

that is the present scenario.

Now, we have (arguably) found evidences of running water. first of all this can also mean that there were flash flood and not permanent rivers which etched those riverine geomorphology. but your point is well taken, if there is a transport of water, then there must be some kind of cyclic activity, albeit not necessarily Earth like. These channels can also be the signatures of a retreating ice age.

unless i see the full topography fo the complete channel, i can not draw a conclusion. i would be able to draw a conclusion, if the rover followed the channel , and made study of it - from end to end
 
  • #10


marty1 said:
Correct me if I am wrong, but don't lava flows erod rock like flowing water too?

there is another factor coming to play, the temperature, and the erosion by lavaflow erosion is rather changing the chemical signature of the contact zone (consider that rocks are poor conductors), and often lava is more viscous than water hence flow is very very slow, hence you will not expect a mechanical erosion like water. for fast flowing lava, it cools down fast too, and a new layer of lava flows over it.
 
  • #11
Could molten rocks get round shapes, without any water flow? Just from volcanic eruptions or from a meteoroid impact?
 
  • #12
I found it very disappointing, and rather strange, that a mission designed to look for past signs of life, finds what is apparently an ancient river bed, complete with pebbles, and doesn't spend more time, and use the macro camera, to try and identify the rock type of those pebbles. Nothing to see here, move along? I thought they would have been jumping with joy at such a discovery.
 
  • #13
@ enthalpy, i am afraid, no. a lquid will take a round drop shape only when
1) either it has a high surface tension, and the medium it is on has a low adhesion (mercury and glass for example) - for lava on rock that is not the case
2) in microgravity, in Mars that is not the case either.
 
  • #14
If you have water running downhill, it was deposited uphill by some process. Ergo, you have a hydrological cycle.

If you have a drug user and a drug seller, you have a drug trade.

No reason to suppose it's earth-like, though.
 
  • #15

Similar threads

Undergrad Is Late Water Flow on Mars Linked to Climate Change or Permafrost Melting?
  • · Replies 3 ·
Replies
3
Views
3K
NASA NASA to Announce Mars Mystery Liquid water today
  • · Replies 64 ·
3
Replies
64
Views
12K
What colors and attributes could alien flora & fauna have?
  • · Replies 15 ·
Replies
15
Views
6K
Mathematica This Week's Finds in Mathematical Physics (Week 228)
  • · Replies 2 ·
Replies
2
Views
3K
Mathematica This Week's Finds in Mathematical Physics (Week 228)
  • · Replies 2 ·
Replies
2
Views
4K
Mathematica This Week's Finds in Mathematical Physics (Week 264)
  • · Replies 6 ·
Replies
6
Views
5K