Mars Ice Deposit Holds as Much Water as Lake Superior(jpl.nasa.gov) |
Mars Ice Deposit Holds as Much Water as Lake Superior(jpl.nasa.gov) |
North and South America have a surface area of about 42.55 million sq km or 4.58x10^14 sq ft (1 foot deep water is obviously 4.58x10^14 cubic feet).
Lake Superior has a volume of 12,100 cubic km or 4.2x10^14 cubic feet.
That's unbelievable!
http://www.wolframalpha.com/input/?i=volume+of+lake+superior...
It struggles with the more esoteric aquifers, and doesn't understand "North and South America" as an object, but still pretty cool.
So take the area of the lake and multiply it by 483, and now it is not surprising that you can cover North+South America with it.
V Lake Superior / (306 * 10^12 * 365) = 26.86 years
About 27 years of entire US water supply assuming no water cycle. Now that I do the math (hopefully I didn't screw it up), I'm not sure that's a big number or a small one actually.
Also puts into perspective just how much water there is on earth.
Or in other words, imagine turning Maine into a fishtank forty stories high that's full of fresh water.
/ducks to avoid projectiles
Apathy is on its way to winning.
(Don't tell Jen.)
Isn't this the next step after turning it off and on again.
Back when we had more mechanical drives, daughterboards, socketed chips and the like, it worked a surprising amount of the time.
Apathy... Maybe that comes with age.
P.S. Not to mention tubes. Yeah, I'm that old.
P.P.S The grandparent was making a reference to a show, and Jen is a character in that show. In case that was confusing anyone.
http://www.wolframalpha.com/input/?i=(40,000+cubic+kilometre...
To skip ahead, the Great Artesian Basin, the largest artesian basin in the world, would be just over 5 feet.
http://www.wolframalpha.com/input/?i=(64,900+cubic+kilometre...
But you don't get those at such low atmospheric pressure. Mars atmospheric pressure is around 600pa. Below 611pa, the boiling point of water drops to the freezing point; you can have ice or steam, but not liquid water.
A mental exercise: Any place on Mars with higher than 600pa pressure?
None?
A glacier that has the pressure to melt ice, would have more than enough pressure to keep it from sublimating. A rough estimate says that a foot or so of ice could provide over 600KPa of pressure, but that doesn't account for any means of keeping the water liquid or the ice solid. However, I wouldn't expect to actually find that on Mars. You might be able to keep water that way for a while until it froze again.
Without a spinning core, Earth would be like Mars.
Of course you can live in caves instead of trying to terraform Mars, but doesn't sound so fun.
I.e. Breathing is of limited utility, if the solar weather still gives you cancer.
Sorry for the overly blunt answer, because I know this isn't the question you're asking, but IMHO the question you're asking is based on a ridiculous premise.
We are polluting the Earth. Yeah, this is really bad for the Earth, and for us, but it isn't going to kill all life here. The thing that a "backup planet" is here to protect against is something like being struck by a meteor, or a plague, or nuclear war. Something where everybody dies very quickly, not something where life changes radically.
I am also not sure that it is possible to 'terraform' Earth. 'Terraform' means 'to make like Earth', and Earth is as Earth-like as is possible, no matter how hot or cold it is.
For example, Elon's speech about Mars colonization gives one answer. Maybe you've got great reasons to disagree with him. Maybe there's someone else you'd like to reply to?
(Hint: folks advocating for Mars think the atmosphere is not unusable.)
To hide from Radiation, one plan is to have 16 feet of soil on top of the habitat [1], and limit outdoor time to just 2 hours a day. Given those levels, I'd argue that it would make better sense to build entirely underground on the Moon. The Moon has a shallower gravity well, much stronger solar flux for power, and is much closer for resupply.
[1] http://www.space.com/21813-mars-one-colony-space-radiation.h...
