This guy says a ticket should cost about $320,000. Can I put it on my Visa card?
And according to Robert Zubrin, colonizing Mars is perfectly feasible, economically speaking. What would Mars have to export? Why, ideas, of course, you silly person.
And of course, Cecil Adams wrote using the knowledge and research available to him at the time.
Maybe it’s time to review the straight dope column? Of course, the announcement of the discovery is still very recent, and I wouldn’t be surprised if other researchers come up with their own explanations, not involving the presence of water, of the geological formations observed on Mars that would seem to indicate the presence of water in more or less recent times.
I believe Marilyn Vos Savant actually covered Giant Nuclear Space Poodles in one of her columns. Well, Cecil?
(anyway, Arnold, you know I’m not trolling here. I just thought it was funny that all I heard last week was, “There’s water on Mars! There’s water on Mars!” so I wondered, “Hey, if they found water, maybe they’ll find some canals, too!” Doncha think that’s funny, Arnold? Huh? Arnold, huh? Doncha think that’s funny?)
Of course I realize that your comment was meant tongue-in-cheeck, Duck Duck Goose. But I decided to adopt a mantle of gravitas and seriousness to see how it would fit on my shoulders. How does it look?
One clarification: They are highly unlikely to discover any true canals on Mars, as a canal is, by definition, made by intelligent beings, and nobody’s even hypothesizing intelligent Martians anymore. I presume that DDG, being well-educated, already knew this, and meant to say “channels”. The fact is, though, that channels on Mars have been known for quite a while, at least since the Viking probes (and possibly one of the Mariners?). We know that there was once liquid water in abundance on the Red Planet, and it caused these formations, which look pretty much the same as dry river beds here on Earth. It’s also possible that DDG was referring to currently active channels, i.e., rivers. In this case, I’m going to have to dissappoint you, Duck. Liquid water can exist on the Martian surface, but it can’t stick around for long. The formations they’re talking about now were formed by water that was already boiling away as it reached the surface.
i believe on of the problems with liquid water on mars is that without a decent atmosphere, water immediately evaporates. i expect that mist does not make a very good channel. it seems to me that liquid water necessitates an atmosphere, but i’m not so sure anyone thinks there was an atmosphere on mares in “geologically recent” time.
Mars’s atmosphere is very thin, only about 1% of Earth’s. But at the bottom of Valles Marineris, six miles below the datum (the equivalent of “sea level” for Mars), it’s much denser, just like the air in Death Valley is denser than the air on top of Mt. Rainier.
If I understand what I’ve read, the air on the canyon floor may be thick enough that water coming up from underground springs can stay liquid, and even pool on the surface.
For a while. Even if it’s really happening in the present-day, it’s got to be a short-lived phenomenon when it does. For one thing, it’s usually too cold for liquid water to occur, but Valles Marineris is near the Equator, so it warms up above 0 degrees Celsius during the daytime every so often.
So water may bubble out, pool during the day, then freeze, then sublime overnight.
this is long, so skip it if you don’t feel technical today.
Everything you said sounded good, but I got to thinking. (I gotta stop that.) So I did a bit of research and learned that the Valles M. is 4 miles deep and 2500 miles long. The grand canyon is 1 mile deep and 500 miles long, for comparison.
Now, four miles is pretty danged deep. But is it enough to make that 1% of the earth atmosphere dense enough ot let water bubble? I didn’t think so, and i don’t actually know because i couldn’t find the answer anywhere.
I did find this, though, from the Mars Global Surveyor Site:
Gullies seen on martian cliffs and crater walls in a small number of high-resolution images from the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) suggest that liquid water has seeped onto the surface in the geologically recent past. The gully landforms are usually found on slopes facing away from mid-day sunlight, and most occur between latitudes 30° and 70° in both martian hemispheres. The relationship to sunlight and latitude may indicate that ice plays a role in protecting the liquid water from evaporation until enough pressure builds for it to be released catastrophically down a slope. The relative freshness of these features might indicate that some of them are still active today–meaning that liquid water may presently exist in some areas at depths of less than 500 meters (1640 feet) beneath the surface of Mars. http://www.msss.com/mars_images/moc/june2000/
So now I think the ice may protect so much liquid water that it ‘bubbles’ out or something and then is able to form the channels before the atmosphere can evaporate it. And that, as you said, would work best in the densest atmosphere available.
Thanks for the cite, emoryj. I was going to post that myself, momentarily. As for the atmosphere: There are formations on Mars that would require ordinary rivers and lakes to form. The usual interpretation of this is that there were, in fact, once rivers and lakes, with the logical consequence that, at one time, Mars’ atmosphere was significantly thicker than it is now. What exactly happened to the atmosphere is a matter of debate; for that matter, we’re not sure why the Earth’s atmosphere is so thin, either (compare Venus). Nobody, however, believes that there are currently any permanent bodies of water on the surface of Mars-- We’re not even sure if these flash springs still occur.
