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#176 2017-02-20 04:38:10

RobertDyck
Member
From: Winnipeg, Canada
Registered: 2002-08-20
Posts: 4,921
Website

Re: Mars Needs Nitrogen

knightdepaix wrote:

can fluroine be located or made?

Various fluorine minerals exist on Earth. Geologists expect to find them on Mars as well. Haven't heard a report yet, but all geologists I spoke with say it's just a matter of time before a Mars probe finds some. Commons ores: fluorspar (CaF2), fluorapatite (Ca5(PO4)3F) and cryolite (Na3AlF6). The last one is a catalyst to smelt aluminum.

knightdepaix wrote:

My own question is if perfluorohydrocarbons destroy ozone. I believe not.

You're correct, the answer is no. Chlorine destroys ozone. CFC containes chlorine but PFC does not.

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#177 2017-02-20 17:53:30

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 10,262

Re: Mars Needs Nitrogen

mars Neon, Xenon, Krypton are trace in the atmospher as it is on earth with the bulk of it being underground as these are heavy elements.

https://phys.org/news/2014-11-xenon.html
https://dorkmission.blogspot.com/2016/0 … -show.html

The isotopic decay test the remaining story to why we do not have large quantities of them.

http://blogs.esa.int/rosetta/2016/06/14 … inventory/

Neon is used in lamps bulbs and the older florescent tubing glass signs. Xenon and Krypton we use in ION drive engines....

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#178 2017-08-23 19:14:20

Dao Angkan
Member
Registered: 2017-08-23
Posts: 3

Re: Mars Needs Nitrogen

Mars atmosphere is currently about 25 trillion tons, or 25 Teratonnes (Tt). This equates to about 6.0 mbar at the datum, although at the depths of Hellas Basin, the pressure is roughly double that.

According to the paper "Radiative-convective model of warming Mars with artificial
greenhouse gases", "Only" 0.002 mbar of super greenhouse gases is required to set off a runaway greenhouse effect. The actual gases would have little effect on pressure themselves, but by releasing the frozen polar CO2 we might expect pressure to double, and with additional CO2 outgassing from regolith, and acidic water reacting with shallow carbonate deposits me might expect more, although it's difficult to say how much. Let's say it doubles the atmosphere again, to 100Tt.

Mars is estimated to have over 5,000Tt of water in polar ice and relatively shallow glaciers, with more even deeper. Enough to cover the planet (if it was flat) in 35m of water. Venus has only 20ppmv of water vapour in it's atmosphere, but as the atmosphere is so dense, then this could still be 5Tt worth, enough to cover the surface (flat) in 1cm of water. Clearly Venus needs more water (or at least hydrogen, which makes up about 11% of water by weight).

So if Martians are electrolysing water to pump oxygen into the atmosphere (I'll assume they have fusion), they might want to export the excess hydrogen to the floating cities of Venus.

Mars/Venus close approach is every 11 months, a 6/7 month trip gives enough time to return at the next window, and leave for Venus again at the window following that, for a round trip every 22 months.

A 500m diameter spherical tanker would have a volume of 65,449,800m³, liquid hydrogen has a density of 70.8 kg/m³, so 4,633,845t/tanker. After unloading the hydrogen at Venus, you could load up with liquid nitrogen at Venus, which has a density of 804 kg/m³, for  52,621,639t/tanker. However, Venus has argon at 70ppmv, which could be about 46Tt worth, and argon is denser still at 1,394 kg/m³ for 91,237,021t/tanker.

If the Martian atmosphere is still so thin that nowhere is even above the Armstrong limit (62mbar), then it might make more sense to import argon first, in order to thicken up the atmosphere quicker.

So let's say that there's a tanker manufacturing plant on Phobos producing 100 tankers/year with a lifetime of 100 years each. Each tanker can make 54 round trips in 99 years before being retired. After 100 years the number of tankers will have risen to 10,000, and from then on remain steady as newly produced tankers replace retired ones.

These 10,000 tankers can make 540,000 round trips every hundred years, we can halve that for the first hundred years as the fleet was building up.

Applying that to the following;
Liquid hydrogen = 2.50Tt
Liquid nitrogen = 28.42Tt
Liquid argon = 49.27Tt

Oxygen produced from water at Mars = 19.86Tt
Water produced from hydrogen at Venus = 22.36Tt

So after the first hundred years we've transported enough hydrogen to Venus to make 11.18Tt of water, tripling the current inventory of 5Tt.
Produced 9.93Tt of oxygen on Mars, and imported 24.635Tt of Argon, adding a total of 34.565Tt to the atmosphere. If we already had 100Tt mainly CO2 atmosphere, then that's enough extra to bring the very lowest altitudes above the Armstrong limit ... no pressure suit needed.

For the second hundred years we exhaust the supply of argon after 43 years;
Liquid argon = 21.365Tt
Oxygen produced from water at Mars = 8.61Tt

Adding another 30Tt of atmosphere the area of land above the armstrong limit continuously expands.

For the remaining 57 years;
Liquid Nitrogen = 16.10Tt
Oxygen produced from water at Mars = 11.25Tt

Atmosphere ;
After 200 years = 192Tt (46mbar at datum / ~92 mbar bottom Hellas)
After 300 years = 240Tt (58mbar at datum / ~116 mbar bottom Hellas)
After 400 years = 288Tt (69mbar at datum / ~138 mbar bottom Hellas)
After 500 years = 337Tt (81mbar at datum / ~162 mbar bottom Hellas)
After 600 years = 385Tt (92mbar at datum / ~184 mbar bottom Hellas)
After 700 years = 433Tt (104mbar at datum / ~208 mbar bottom Hellas)
After 800 years = 482Tt (116mbar at datum / ~232 mbar bottom Hellas)
After 900 years = 530Tt (127mbar at datum / ~254 mbar bottom Hellas)
After 1,000 years = 578Tt (139mbar at datum / ~278 mbar bottom Hellas)

After 1,000 years the atmosphere at the bottom of Hellas would be;

N2: 134 mbar (48.25%)
O2: 91 mbar (32.7%)
CO2: 35 mbar (12.6%)
AR: 18 mbar (6.45%)

This would be a breathable atmosphere (equivalent to 7,000m on Earth ... the death zone is said to start at 8,000m / 75 mbar O2), although you probably wouldn't want to spend more than a few days without supplementary oxygen.

Venus now has ~217Tt of water, up from ~5Tt originally, if they've cooled it down and sequestered much of the carbon atmosphere they now have enough water to cover the planet in 40cm+ of water. Mars has lost over 200Tt of water, but still has nearly 5,000Tt left, and has increased it's atmosphere  by nearly 500Tt.

So first 100 years was spent warming Mars, next 1,000 years spent gradually pressurising higher elevations on Mars to above the Armstrong limit, and the next 2,000 years can be spent gradually oxygenating higher elevations to breathable atmospheres.

After 2,000 years = 1,061Tt (255mbar at datum / ~509 mbar bottom Hellas)

N2: 140 / 279 mbar (54.81%)
O2: 90 / 179 mbar (35.20%)
CO2: 17 / 34 mbar (6.61%)
AR:  9 / 17 mbar (3.38%)

Datum is now breathable (but not really "livable" yet), bottom of Hellas has partial pressure of Oxygen close to Earth (18% Vs 21%).

After 3,000 years = 1,544Tt (371mbar at datum / ~741 mbar bottom Hellas)

N2: 212 / 423 mbar (57.14%)
O2: 134 / 267 mbar (36.09%)
CO2: 17 / 33 mbar (4.48%)
AR:  8 / 17 mbar (2.29%)

You'd probably want to stop pumping oxygen into the atmosphere now. 26.7% O2 partial pressure at lowest elevations and 3.3% of CO2, much of which will eventually be photosynthesised into O2. <30% should be fine. At the datum O2 levels are equivalent to 3,800m on Earth. Highest peaks still require pressure suits, but probably not worth spending another 2,000 years importing nitrogen just to make mountains climbable without pressure suits.

There's a lot of technical issues that I haven't addressed here, but on a logistical level at least, I think that importation of nitrogen is plausible over 100 year+ timescales, and the good thing is that you don't have to wait a long time to see the benefits, every delivery slightly increases the land area of viable liquid water /survivable pressure / breathable atmosphere, so that people are motivated to continue the process over the centuries and millennia required.

Last edited by Dao Angkan (2017-08-23 19:31:55)

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#179 2017-08-24 04:37:30

louis
Member
From: UK
Registered: 2008-03-24
Posts: 2,340

Re: Mars Needs Nitrogen

Very interesting proposal. But I think I would look at this from another way round - how much nitrogen do we need on Mars in the atmosphere? Do we really need to replicate the Earth proportions?  Are there other inert gases we can use?  Nitrogen in the air is not absolutely essential for plant growth if we can deliver it through the soil and there are bacteria that can do that (taking it from the air).

I prefer a low resource solution  - using solar sails to reflect solar radiation on to Mars and thus heat up the planet as quickly as possible.
The issue then is what sort of atmosphere you would end up with? We might be able to influence that by directing the reflected solar radiation on to particular parts of the planet, beginning with the north polar region.


Dao Angkan wrote:

Mars atmosphere is currently about 25 trillion tons, or 25 Teratonnes (Tt). This equates to about 6.0 mbar at the datum, although at the depths of Hellas Basin, the pressure is roughly double that.

According to the paper "Radiative-convective model of warming Mars with artificial
greenhouse gases", "Only" 0.002 mbar of super greenhouse gases is required to set off a runaway greenhouse effect. The actual gases would have little effect on pressure themselves, but by releasing the frozen polar CO2 we might expect pressure to double, and with additional CO2 outgassing from regolith, and acidic water reacting with shallow carbonate deposits me might expect more, although it's difficult to say how much. Let's say it doubles the atmosphere again, to 100Tt.

Mars is estimated to have over 5,000Tt of water in polar ice and relatively shallow glaciers, with more even deeper. Enough to cover the planet (if it was flat) in 35m of water. Venus has only 20ppmv of water vapour in it's atmosphere, but as the atmosphere is so dense, then this could still be 5Tt worth, enough to cover the surface (flat) in 1cm of water. Clearly Venus needs more water (or at least hydrogen, which makes up about 11% of water by weight).

So if Martians are electrolysing water to pump oxygen into the atmosphere (I'll assume they have fusion), they might want to export the excess hydrogen to the floating cities of Venus.

Mars/Venus close approach is every 11 months, a 6/7 month trip gives enough time to return at the next window, and leave for Venus again at the window following that, for a round trip every 22 months.

A 500m diameter spherical tanker would have a volume of 65,449,800m³, liquid hydrogen has a density of 70.8 kg/m³, so 4,633,845t/tanker. After unloading the hydrogen at Venus, you could load up with liquid nitrogen at Venus, which has a density of 804 kg/m³, for  52,621,639t/tanker. However, Venus has argon at 70ppmv, which could be about 46Tt worth, and argon is denser still at 1,394 kg/m³ for 91,237,021t/tanker.

If the Martian atmosphere is still so thin that nowhere is even above the Armstrong limit (62mbar), then it might make more sense to import argon first, in order to thicken up the atmosphere quicker.

So let's say that there's a tanker manufacturing plant on Phobos producing 100 tankers/year with a lifetime of 100 years each. Each tanker can make 54 round trips in 99 years before being retired. After 100 years the number of tankers will have risen to 10,000, and from then on remain steady as newly produced tankers replace retired ones.

These 10,000 tankers can make 540,000 round trips every hundred years, we can halve that for the first hundred years as the fleet was building up.

Applying that to the following;
Liquid hydrogen = 2.50Tt
Liquid nitrogen = 28.42Tt
Liquid argon = 49.27Tt

Oxygen produced from water at Mars = 19.86Tt
Water produced from hydrogen at Venus = 22.36Tt

So after the first hundred years we've transported enough hydrogen to Venus to make 11.18Tt of water, tripling the current inventory of 5Tt.
Produced 9.93Tt of oxygen on Mars, and imported 24.635Tt of Argon, adding a total of 34.565Tt to the atmosphere. If we already had 100Tt mainly CO2 atmosphere, then that's enough extra to bring the very lowest altitudes above the Armstrong limit ... no pressure suit needed.

For the second hundred years we exhaust the supply of argon after 43 years;
Liquid argon = 21.365Tt
Oxygen produced from water at Mars = 8.61Tt

Adding another 30Tt of atmosphere the area of land above the armstrong limit continuously expands.

For the remaining 57 years;
Liquid Nitrogen = 16.10Tt
Oxygen produced from water at Mars = 11.25Tt

Atmosphere ;
After 200 years = 192Tt (46mbar at datum / ~92 mbar bottom Hellas)
After 300 years = 240Tt (58mbar at datum / ~116 mbar bottom Hellas)
After 400 years = 288Tt (69mbar at datum / ~138 mbar bottom Hellas)
After 500 years = 337Tt (81mbar at datum / ~162 mbar bottom Hellas)
After 600 years = 385Tt (92mbar at datum / ~184 mbar bottom Hellas)
After 700 years = 433Tt (104mbar at datum / ~208 mbar bottom Hellas)
After 800 years = 482Tt (116mbar at datum / ~232 mbar bottom Hellas)
After 900 years = 530Tt (127mbar at datum / ~254 mbar bottom Hellas)
After 1,000 years = 578Tt (139mbar at datum / ~278 mbar bottom Hellas)

After 1,000 years the atmosphere at the bottom of Hellas would be;

N2: 134 mbar (48.25%)
O2: 91 mbar (32.7%)
CO2: 35 mbar (12.6%)
AR: 18 mbar (6.45%)

This would be a breathable atmosphere (equivalent to 7,000m on Earth ... the death zone is said to start at 8,000m / 75 mbar O2), although you probably wouldn't want to spend more than a few days without supplementary oxygen.

Venus now has ~217Tt of water, up from ~5Tt originally, if they've cooled it down and sequestered much of the carbon atmosphere they now have enough water to cover the planet in 40cm+ of water. Mars has lost over 200Tt of water, but still has nearly 5,000Tt left, and has increased it's atmosphere  by nearly 500Tt.

So first 100 years was spent warming Mars, next 1,000 years spent gradually pressurising higher elevations on Mars to above the Armstrong limit, and the next 2,000 years can be spent gradually oxygenating higher elevations to breathable atmospheres.

After 2,000 years = 1,061Tt (255mbar at datum / ~509 mbar bottom Hellas)

N2: 140 / 279 mbar (54.81%)
O2: 90 / 179 mbar (35.20%)
CO2: 17 / 34 mbar (6.61%)
AR:  9 / 17 mbar (3.38%)

Datum is now breathable (but not really "livable" yet), bottom of Hellas has partial pressure of Oxygen close to Earth (18% Vs 21%).

After 3,000 years = 1,544Tt (371mbar at datum / ~741 mbar bottom Hellas)

N2: 212 / 423 mbar (57.14%)
O2: 134 / 267 mbar (36.09%)
CO2: 17 / 33 mbar (4.48%)
AR:  8 / 17 mbar (2.29%)

You'd probably want to stop pumping oxygen into the atmosphere now. 26.7% O2 partial pressure at lowest elevations and 3.3% of CO2, much of which will eventually be photosynthesised into O2. <30% should be fine. At the datum O2 levels are equivalent to 3,800m on Earth. Highest peaks still require pressure suits, but probably not worth spending another 2,000 years importing nitrogen just to make mountains climbable without pressure suits.

There's a lot of technical issues that I haven't addressed here, but on a logistical level at least, I think that importation of nitrogen is plausible over 100 year+ timescales, and the good thing is that you don't have to wait a long time to see the benefits, every delivery slightly increases the land area of viable liquid water /survivable pressure / breathable atmosphere, so that people are motivated to continue the process over the centuries and millennia required.


Let's Go to Mars...Google on: Fast Track to Mars blogspot.com

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#180 2017-08-24 17:21:50

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 10,262

Re: Mars Needs Nitrogen

PTbyAtMass.gif

The gasseous elements are mostly in the yellow color, such that the heavier the elemental mass then the more benefit man would get from it when teraforming if they are not harmful in concentration levels and not as compound combinations.

The fact that mars has only a gravity of  3.711 m/s² as compared to earths very strong 9.8 m/s²


http://lasp.colorado.edu/~bagenal/3720/ … EVM-4.html

  • Pressures, scaleheights
                                VENUS     EARTH      MARS
    SURFACE PRESSURE (bar) 92             1            0.006
    SCALEHEIGHT (km)          16             8             11
    COLUMN MASS (kg/m2)    1.0E+06     1.0E+04     1.6E+02
    TOTAL MASS (kg)              4.8E+20      5.2E+18     2.3E+16
    COLUMN No. DENSITY (/m2) 1.5E+31   2.2E+29    2.3E+27
    SURFACE No. DENSITY (/m3) 9.01E+26 2.52E+25 1.95E+23
    SURFACE DENSITY (kg/m3)     6.58E+01 1.21E+00  1.42E-02

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#181 2017-08-25 15:17:04

Dao Angkan
Member
Registered: 2017-08-23
Posts: 3

Re: Mars Needs Nitrogen

louis wrote:

Very interesting proposal. But I think I would look at this from another way round - how much nitrogen do we need on Mars in the atmosphere? Do we really need to replicate the Earth proportions?  Are there other inert gases we can use?  Nitrogen in the air is not absolutely essential for plant growth if we can deliver it through the soil and there are bacteria that can do that (taking it from the air).

I prefer a low resource solution  - using solar sails to reflect solar radiation on to Mars and thus heat up the planet as quickly as possible.
The issue then is what sort of atmosphere you would end up with? We might be able to influence that by directing the reflected solar radiation on to particular parts of the planet, beginning with the north polar region.

If you don't want to import then you're stuck with C02, 02, and N2 for substantially thickening the atmosphere (if we ignore toxic gases like S02). Oxygen is available in  virtually unlimited supply from regolith and water ice. "Impact processing of nitrogen on early Mars" estimates ∼30 mbars of N2 fixed as nitrates in the regolith, which fits with the findings of "Evidence for indigenous nitrogen in sedimentary and aeolian deposits from the Curiosity rover investigations at Gale crater, Mars". If you could bake that all out of the regolith and convert to N2 and 02 it would be quite useful. There's currently about 6 mbars of CO2 in the atmosphere, with perhaps the same again frozen. Carbon is also locked up in carbonates, some of which should produce CO2 once liquid water is present. It's not clear how extensive or how accessible the carbonate deposits are, so it's difficult to estimate an upper figure for this, but 30 mbar of CO2 might well be possible.

If you had a 120 mbar atmosphere of
O2: 60 mbar
N2: 30 mbar
CO2: 30 mbar

Then bottom of Hellas would be ∼240 mbar
O2: 120 mbar
N2: 60 mbar
CO2: 60 mbar

Oxygen equivalent of 4,800m on Earth (La Rinconada, Peru has a pop. of 50k @ 5,100m). CO2 is a bit high, but should be tolerable with acclimatisation. O2 could be continuously increased to bring higher elevations to breathable levels.

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#182 2017-08-26 11:06:44

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 10,262

Re: Mars Needs Nitrogen

https://en.wikipedia.org/wiki/Atmosphere_of_Earth

https://upload.wikimedia.org/wikipedia/ … ereBig.jpg

Diagram of Earth's atmosphere (layers to scale). Distance from the surface to the top of the stratosphere is just under 1% of Earth's radius.

Excluding the exosphere, the atmosphere has four primary layers, which are the troposphere, stratosphere, mesosphere, and thermosphere.[9] From highest to lowest, the five main layers are:

    Exosphere: 700 to 10,000 km (440 to 6,200 miles)
    Thermosphere: 80 to 700 km (50 to 440 miles)[10]
    Mesosphere: 50 to 80 km (31 to 50 miles)
    Stratosphere: 12 to 50 km (7 to 31 miles)
    Troposphere: 0 to 12 km (0 to 7 miles)[11]

Each is made up of a different gas mixture..

https://upload.wikimedia.org/wikipedia/ … 62.svg.png

Comparison of the 1962 US Standard Atmosphere graph of geometric altitude against air density, pressure, the speed of sound and temperature with approximate altitudes of various objects.

Earth Mean radius 6371.0 km (3958.8 mi)
Surface gravity 9.807 m/s2 (1 g; 32.18 ft/s2)
Escape velocity 11.186 km/s (40270 km/h; 25020 mph)

Mars Mean radius 3,389.5±0.2 km
Surface gravity 3.711 m/s²
Escape velocity 5.027 km/s

Scale atmospheric content to mars radius and gravity makes for a much lower level of pressure even if we make it breathable.

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#183 2017-08-26 11:50:05

Dao Angkan
Member
Registered: 2017-08-23
Posts: 3

Re: Mars Needs Nitrogen

Note that Mars only has 28% of the surface area of Earth, with 38% of the gravity. If Mars had Earth's atmosphere, the pressure would be higher on Mars.

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#184 2017-08-26 16:53:02

louis
Member
From: UK
Registered: 2008-03-24
Posts: 2,340

Re: Mars Needs Nitrogen

Thanks for the expert analysis, Dao.

Isn't water vapour a factor as well?  What's the max amount of water vapour we could carry in a terraformed Mars atmosphere? I read that it can be up to 4% in hot equatorial zones on Earth. Could it be higher on Mars?

One thing I do recall is that people at 5000 metres plus elevation have adapted for reproduction at that height...people who live closer to sea level can't reproduce successfully at that height, so that's something to bear in mind.


Dao Angkan wrote:
louis wrote:

Very interesting proposal. But I think I would look at this from another way round - how much nitrogen do we need on Mars in the atmosphere? Do we really need to replicate the Earth proportions?  Are there other inert gases we can use?  Nitrogen in the air is not absolutely essential for plant growth if we can deliver it through the soil and there are bacteria that can do that (taking it from the air).

I prefer a low resource solution  - using solar sails to reflect solar radiation on to Mars and thus heat up the planet as quickly as possible.
The issue then is what sort of atmosphere you would end up with? We might be able to influence that by directing the reflected solar radiation on to particular parts of the planet, beginning with the north polar region.

If you don't want to import then you're stuck with C02, 02, and N2 for substantially thickening the atmosphere (if we ignore toxic gases like S02). Oxygen is available in  virtually unlimited supply from regolith and water ice. "Impact processing of nitrogen on early Mars" estimates ∼30 mbars of N2 fixed as nitrates in the regolith, which fits with the findings of "Evidence for indigenous nitrogen in sedimentary and aeolian deposits from the Curiosity rover investigations at Gale crater, Mars". If you could bake that all out of the regolith and convert to N2 and 02 it would be quite useful. There's currently about 6 mbars of CO2 in the atmosphere, with perhaps the same again frozen. Carbon is also locked up in carbonates, some of which should produce CO2 once liquid water is present. It's not clear how extensive or how accessible the carbonate deposits are, so it's difficult to estimate an upper figure for this, but 30 mbar of CO2 might well be possible.

If you had a 120 mbar atmosphere of
O2: 60 mbar
N2: 30 mbar
CO2: 30 mbar

Then bottom of Hellas would be ∼240 mbar
O2: 120 mbar
N2: 60 mbar
CO2: 60 mbar

Oxygen equivalent of 4,800m on Earth (La Rinconada, Peru has a pop. of 50k @ 5,100m). CO2 is a bit high, but should be tolerable with acclimatisation. O2 could be continuously increased to bring higher elevations to breathable levels.


Let's Go to Mars...Google on: Fast Track to Mars blogspot.com

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#185 2017-08-26 17:40:39

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 10,262

Re: Mars Needs Nitrogen

Thats when we change the hieght via volume to radius of earth versus mars which would increase the column hieght and its pressure seen on ars surface. Thats not how a mars atmospher will be when we try to teraform mars as gravity and content will matter more.

Using the 1% radius as the max hieght of mars atmosphere would mean that its starts at just 338.95±0.2 km and from what we have measured mars is around 6.8 miles (11 km) with its average pressure around 600 pascals (0.087 psi). Which tells me that escape velocity is being reached to have allowed so much of it to disappear.

That said gravity must also be a factor in the final atmospheres hieght. So mars/ earth would mean a factor of reduction of approximate 38% giving a new height for mars of just 130 km at best. To give a column pressure of about 1.088 psi.

Now if mars did have the 5 layers as earth does the layers might have this for measurement
Exosphere: 130 km
Thermosphere: 3.08  km
Mesosphere: 1.95 km
Stratosphere: 0.458 km
Troposphere: 0 to 0.458 km

The lowest would be breatable air with the other just being made up of what will stick around below escape velocity. Of course column mass would rise and mars would have a surface pressure of less than 5 psi at is most so would someone review these numbers...

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