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Mars Canals May Not Mean Water
Ant writes "
NASA scientists are beginning to suspect
that the widely reported water channels on Mars were actually caused by
jets of carbon dioxide.
At a conference at NASA's Ames Research Center, NASA researcher
Robert Haberle said scientists now think Martian gullies believed to have
been carved by liquid water may instead have been produced by flutes of
liquid carbon dioxide, a finding that could have profound effects on future
missions to the Red Planet." This story has been bouncing around for a while.h
Comment removed based on user account deletion
I thought it was Venus that had the canals... What? That's Venice? My bad...
</stupid>
Free music from Jack Merlot.
"This story has been bouncing around for a while.h"
WOW!, i can't wait until i can see the while.c then!
I would have thought that the low pressure/temperature of the Martian atmosphere would cause most of the liquid CO2 to become gaseous and the rest to solidify into CO2 snow (dry ice).
If I remember correctly, this is how dry ice is made now. Cool CO2 enough that it becomes liquid, and then shoot it out into a lower pressure. The lower pressure makes most of it turn into a gas, but to get the thermal energy necessary to do that, it grabs heat from the rest, which solidifies.
Is there any evidence of a powdering of CO2 snow near those canals? Or were they formed long enough ago that any snow would have sublimed off into the atmosphere...
It may look like I'm doing nothing, but I'm actively waiting for my problems to go away.
--Scott Adams
What's important is not whether the canals were water.
We have plenty of evidence that water exists on Mars,
independent of whether the canals themselves were
caused by water (e.g. evidence from the polar ice-caps.
The presence of liquid CO2 on
Mars is almost as useful as We have plenty of
water would be, since liquid evidence that water
CO2 has so many industrial exists on Mars,
uses. The presence of the independent of whether
two together is good news to the canals themselves
this reader, I assure you. were caused by water
A planet with so much
geological activity in its history and potential for
terraforming won't be set back by a discovery such as
this.
-- Anne Marie
The triple point for carbon dioxide occurs at 5.11 atmospheres. Maybe there are underground CO2 "aquifers" on Mars, but these aren't underground channels we're talking about, they're surface features. For liquid CO2 to exist on the Martian surface, it would have to be sitting under over 50 meters of frozen CO2 crust, even if there were an atmosphere as dense as Earth's on top of that.
I think he meant This_story_has_been_bouncing_around_for_a_while.h, which contains the prototype for the this_is_old_news() function.
-Daniel
One, this discusses some channels and surface features of craters, not of the whole surface of Mars.
Two, as many people have discussed, CO2 would not be viable as liquid for almost any time at all, in the Martian atmosphere.
However, since they appear in the walls of craters, these channel markings may not have always been surface features. If formed while rock was still overhead, underground pressures may have indeed been high enough to support liquid CO2. A crater is a surface defect caused by a collision.
For all we know, this is the Martian geological equivalent of termite tunnels through ironwood: we don't see the damage until we crack open the outer layers.
I don't have the liberty to check the whole set of data and findings that the scientists have gathered. And neither do 99% of us. Rather than jump to say, on limited information, "gee, that's impossible," I invite people to think about what may be possible. Critical thinking doesn't have to be destructive of theories.
[
Hoffman has a very informative website at http://irian.geolo gy. latrobe.edu.au/~nhoffman/Mars/index.html, much of it comprehensible to non-planetary scientists like me.
PS: can people PLEASE stop saying "canals" when they mean "channels"? It's important: "canals" implies artificiality, "channels" can be natural in origin. (Damn the Italian language for having "canali" as the word for channels.) There are NO canals on Mars, but there are channels.
The real Captain Avatar is a fictional character, so I suppose he doesn't mind if I impersonate him.
I think water is the "right" guess for the cause of the channels. Water is really the only substance we have direct evidence (actually this is not true lava does the same) building channels on earth.
It should be pointed out that when it comes to geological process it is very rare that we have direct observation and/or good experimental evidence to explain the geomorphology of an area.
That being said we can to a pretty good job of explaining things like the grand canyon, even though we haven't been watching it for several million years.
NASA made headlines in June when photographs from the Mars Global Surveyor, a satellite orbiting the planet, showed scores of gullies, channels and deltas on the sides of numerous Martian craters.
I don't think they were attempting to say that all the chanels on Mars were formed by carbon dioxide, just the ones on the sides of the craters. The major gullies on the surface may still have been from water at some point in the far past.
Dirty Pirate Hooker
This is known in the science trade as salami science: slice your work really thin and publish lots of short, incomplete articles so your c.v. looks more impressive. Why can't Wired write a single carefully researched Mars article instead of lots and lots of shallow ones?
The Wired articles are also pretty pathetic because they never include any out-going links to more substantial academic or government articles. If Wired is supposed to be an example of really modern internet journalism, why do they use the web as if it was made of dead trees?
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