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Humans Will Never Colonize Mars
The suggestion that humans will soon set up bustling, long-lasting colonies on Mars is something many of us take for granted. What this lofty vision fails to appreciate, however, are the monumental—if not intractable—challenges awaiting colonists who want to permanently live on Mars. Unless we radically adapt our brains and bodies to the harsh Martian environment, the Red Planet will forever remain off limits to humans.
Mars is the closest thing we have to Earth in the entire solar system, and that's not saying much.
The Red Planet is a cold, dead place, with an atmosphere about 100 times thinner than Earth's. The paltry amount of air that does exist on Mars is primarily composed of noxious carbon dioxide, which does little to protect the surface from the Sun's harmful rays. Air pressure on Mars is very low; at 600 Pascals, it's only about 0.6 percent that of Earth. You might as well be exposed to the vacuum of space, resulting in a severe form of the bends—including ruptured lungs, dangerously swollen skin and body tissue, and ultimately death. The thin atmosphere also means that heat cannot be retained at the surface. The average temperature on Mars is -81 degrees Fahrenheit (-63 degrees Celsius), with temperatures dropping as low as -195 degrees F (-126 degrees C). By contrast, the coldest temperature ever recorded on Earth was at Vostok Station in Antarctica, at -128 degrees F (-89 degrees C) on June 23, 1982. Once temperatures get below the -40 degrees F/C mark, people who aren't properly dressed for the occasion can expect hypothermia to set in within about five to seven minutes.
(Score: 2) by c0lo on Thursday August 01 2019, @10:39PM (23 children)
What's your question again? Less substance (thin atmosphere) will retain less heat.
Less substance will also make less likely the re-absorbtion of IR emitted by a cooling-down molecule - the radiative heat loss is faster.
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 0) by Anonymous Coward on Thursday August 01 2019, @11:35PM (22 children)
.95/.0004 * 61/1000= 145x more CO2 in the martian atmosphere than in earths. Mars atmosphere also has only 1/206 the volume of Earths so that means the CO2 is 30,000x denser there. Still, it can't retain heat?
(Score: 2) by c0lo on Thursday August 01 2019, @11:49PM (21 children)
I don't follow what your numbers mean. More as in net amount or what?
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 1, Interesting) by Anonymous Coward on Thursday August 01 2019, @11:56PM (1 child)
I'm using surface pressure as a proxy for total number of molecules. Earth has 1000 mbar atmosphere with .04% CO2. Mars has a 61 mbar atmosphere of 95% CO2. This works out to 145x more CO2 molecules in the Martain atmosphere.
(Score: 2, Informative) by Anonymous Coward on Friday August 02 2019, @12:09AM
So your science understanding is lacking. c0lo already explained above, so my take is you are trolling in order to make some kind of "gotcha" with CO2 not being the problem here on Earth.
(Score: 0) by Anonymous Coward on Friday August 02 2019, @12:14AM (18 children)
If we fill one water bottle up with Earth air and another up with Mars air, the latter will contain 30,000x more molecules of CO2.
(Score: 2) by c0lo on Friday August 02 2019, @01:00AM (17 children)
And your point is?
Homework: list the 3 major specific differences between Earth and Mars.
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 0) by Anonymous Coward on Friday August 02 2019, @01:10AM (16 children)
The point is that IR photons are 30k times more likely to encounter a CO2 molecule on Mars than on earth.
(Score: 2) by c0lo on Friday August 02 2019, @02:03AM (15 children)
And so...?
(Did you do your homework yet?)
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 0) by Anonymous Coward on Friday August 02 2019, @02:19AM (14 children)
So how is this not trapping the heat?
Homework:
1) Mars has a high CO2 atmosphere
2) Mars has no magnetic field
3) Mars has a thin atmosphere
4) Mars is farther from the sun
5) Mars is cold
1) Venus has a high CO2 atmosphere
2) Venus has no magnetic field
3) Venus has a thick atmosphere
4) Venus is closer to the sun
5) Venus is hot
Conclusion: distance to the sun and atmosphere thickness make it cold/hot.
(Score: 2) by c0lo on Friday August 02 2019, @02:25AM (10 children)
You mean, how is this not trapping as much heat as Earth does?
Then maybe the next question will help orient you: how come the differential between day and night temperatures are higher in the desert than it is in the jungle?
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 0) by Anonymous Coward on Friday August 02 2019, @03:19AM (9 children)
Because water has a high heat capacity which slows the rate of warming/cooling, ie there is more thermal inertia. Compare to the moon with no atmosphere that quickly gets both much warmer and colder than the Earth and Venus where the difference between day and night temperatures on are nearly zero, despite that one day is about a year long. Even the latitude gradient on Venus is very weak.
(Score: 2) by c0lo on Friday August 02 2019, @04:32AM (8 children)
Mmmm... on my last visit there, I can't remember to be seeing free water on the surface of Mars; and whatever water exists is closer to the poles (thus low incidence cosine).
Maybe that's one cause for which Mars is colder, in spite of a higher CO2 amount? Could there be others?
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 0) by Anonymous Coward on Friday August 02 2019, @04:48AM (7 children)
7) No water on Mars
7) No water on Venus
Mars cold, Venus hot. Sorry, lack of water doesn't explain it.
(Score: 2) by c0lo on Friday August 02 2019, @05:53AM (6 children)
[citation needed]
---
Venus atmosphere [wikipedia.org]
Estimated water in Venus'es atmosphere = 9.6 × 1012 tonnes
(for comparison [wikipedia.org]: "at any given time, about 20 × 1012 tonnes of this is in the form of water vapor in the Earth's atmosphere")
Ummm... you were sayin'?
---
Now, look, this and your initial
I'll ask you to demonstrate first your assertion that "CO2 fails to maintain heat" on Mars. Mind you, "maintain heat" != "maintain temperature"
Even in a simplified model, for an apples-to-apples comparison, assume the Mars temperature is given just by its atmosphere.
Then recall Gay-Lussac's law and assume a pressure equal to that of Earth (to equalize the amount of substance in the unit of volume with that on Earth).
Min temp on Mars = -126C lets say 150K
Pressure: Mars = 6 millibar, Earth = 1000mbarr
You'll get the "temperature on Mars at equiv Earth atm pressue" of 150K/6mbarr*1000mbarr=25000K.
That is, a mol of CO2 on Mars is heated higher (has more energy) than a mol of CO2 on Earth.
(a good thing, then, the atm on Mars is so rarefied, otherwise Mars atmosphere would glow brighter than the Sun @6000K - grin)
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 0) by Anonymous Coward on Friday August 02 2019, @06:22AM (4 children)
Water that stays evaporated isn't contributing to the thermal inertia other than via increasing the air pressure like adding any other molecule would do. In the jungle its all the water evaporating during the day and condensing at night that stabilizes the temperature.
And your 25,000 K temperature on Mars w 1000 bar atmosphere is nonsense. Venus also has 95% CO2 and has the temperature of ~340 K at 1000 mbar pressure (altitude ~ 40 km). This relationship is given quite easily by Stefan-Boltzmann law.
I give this in a comment above. Using earth surface pressure and temperature we expect: 288*(1/.723^2)^0.25
(Score: 2) by c0lo on Friday August 02 2019, @07:37AM (3 children)
Of course it is nonsensical, starting from invalid assumptions (all the energy captured by Mars is done by atmosphere only, soil doen't contribute, ignoring the energy captured in chemical bonds - those perchlorates [wikipedia.org]? Pretty energetic molecules.) one can't get valid results.
But it does demonstrate that the energy captured by one molecule of CO2 on Mars is likely higher than the one on Earth - where the collision with the other molecules will distribute this energy to other components of the system (and, conversely, "store" energy when the transfer happens towards the CO2 molecule).
And your point is?
I didn't see any consideration made by you on the speed of a CO2 molecule in Venus atm (Maxwell distribution - correlates with how a human or contact thermometer "feels" temperature), not the energy of that molecule in the gravitational field (Bolzmann distribution - determines the "thickness" of the atmosphere [wordpress.com] and thus contributes to the distribution of pressure with the altitude), neither the distribution of energy on the vibration modes of a CO2 molecule (IR emission when it emission happens). I haven't seen any considerations of the distribution of energy across other gases that makes up Venus atmosphere, or the interaction of atm with Venusian soil, nor the energy stored due to the separation of charges (which occasionally trigger lightnings and releases some energy in UV/bremsstrahlung), or how much in Venuses winds/storms or in creation/destruction of that sulphuric acid. No consideration whatsoever on day/night or seasonal cycles and the ways the energy is stored or dissipated over these cycles).
All of them and many others happens because the energy pumped by the Sun, yet I don't see any care for you to consider their contribution or to demonstrate that contribution can be ignored.
All I have seen from you is "Why doesn't CO2 retain heat on Mars?" without any proof this assertion is true.
Why the fuck I'm even wasting my time with you?
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 0) by Anonymous Coward on Friday August 02 2019, @12:25PM (2 children)
Yep, there is no need to consider any of that stuff. It all cancels out once an atmosphere reaches steady state when averaging over a large enough area and timeframe. Eg, maybe CO2 has some warming effect but in repsonse then the system creates more clouds to block insolation so the equilibrium temperature is maintained. All that matters in the end is pressure and insolation.
Do we need to measure the speed of H20 molecules in your blood to know your average body temperature is about 37.2?
(Score: 0) by Anonymous Coward on Friday August 02 2019, @04:52PM (1 child)
I'm yet to see the atmosphere of a planet in that "steady state" that you assert.
(Score: 0) by Anonymous Coward on Friday August 02 2019, @05:28PM
Well, that is your problem... Just look at the temperature of Venus is across day and night sides for the same pressure.
(Score: 0) by Anonymous Coward on Friday August 02 2019, @06:32AM
Mars temp if it had 1000 mbar atmosphere would be about 288*(1/1.52)^0.5 = 234 K. As Venus shows, 95% CO2 or .04% CO2 makes no net difference.
(Score: 0) by Anonymous Coward on Friday August 02 2019, @02:42AM (2 children)
You may want to add to your list: Earth radius: 6,371 km Mars radius: 3,389.5 km. Ratio between the cross-sections Mars/Earth: 28%
Consider this with the consequence of different distances to the Sun - solar flux: Earth 1353 W/sqm Mars 586 W/sqm, ratio Mars/Earth: 38%. You'll get a ratio between the total energy received from the Sun, Mars/Earth = 10.5%
(Score: 0) by Anonymous Coward on Friday August 02 2019, @03:23AM (1 child)
Earth is of similar size to Venus so this doesn't help much.
(Score: 0) by Anonymous Coward on Friday August 02 2019, @04:34AM
Of course Venus being about the same size of Earth doesn't help Mars, did you expect it to?