"Guys, are you sure this is breathable?"

[marx]

While out exploring, I've recently found an interesting little Earth-like world. At first glance, it seemed to be a rather typical one. But then I looked at the atmosphere part:

Spoiler

I can just imagine the first colonists who are about to embark onto the surface. One of them checks the read-outs, and asks the others: "Uh, guys, are you absolutely sure that the atmosphere is breathable?"

 

[Traveller_GG]

Well if the colonists were fish they'd be fine...

"suitable for water-based life"

 

[ProTankerDestruction]

1.32 Atmospheres? Am I just stupid or does that sound dumb.

 

[Inhumierer]

Doesn't sound dumb to me.

 

[MarcusVatta]

As far as breathing is concerned, one noble gas is the same as another (in that it won't interact with our biology), so argon and nitrogen are effectively the same. 14..9% oxygen is lower than our 20.9%, but we only use about 5% when we breathe, so that should be fine. 1.32 atmos is what Scuba divers breathe at a depth of 3 meters, so no problem there.

Basically, yeah, it's breathable.

 

[Ziljan]

1.32 Atmospheres? Am I just stupid or does that sound dumb.

Surface pressures are measured in Earth Atmospheres. Just like accelerations are measured in terms of earth gravity. The atmospheric pressure on the surface of this planet is 1.32 times the sea-level pressure on Earth.

Argon isn't poisonous, but it is heavier than O2, so it could suffocate you if the O2 couldn't reach the bottom of your lungs. If you weren't at sea level, then you'd probably be OK for a while until the Argon built up in your lungs. Most of the Argon would be in the lowest section of atmosphere, but it would still rise due to turbulence and weather patterns. So being in a low pressure system could be deadly.

 

[Bunkerkind Anni]

1.32 Atmospheres? Am I just stupid or does that sound dumb.

hm, thats a little higher preassure then at sea-level on earth. maybe what someone in a submarine experiences.

whats so special about that planet? i cannot see it.
the concentration of argon is significantly higher then on earth. i can't see how that would lead to a high pitch voice, unless someone mistakes argon or nitrogen to helium...

 

[Yaffle]

It's not % oxygen that's important, it's partial pressure for humans.

Argon is inert, won't harm anyone. Our atmosphere has a trace of it.

 

[CMDR AKIRA MASAKARI]

37.7% of argon would make you choke and maybe make impossible to light a match, at least at sea level. That planet should be terraformed before removing suites. AFAIK there are techniques to extract argon from the atmosphere, maybe in a sci-fi setting they can be implemented on a planetary scale. To my knowledge it doesn't change the pitch of your voice tough.

- - - Updated - - -

Argon is inert, won't harm anyone. Our atmosphere has a trace of it.

Argon is way havier than oxygen, it would occupy the base of your lungs impeding CO2-O2 Exchange and you would die in matter of minutes.
In our atmosphere it's 0.92%, so its effect are negletable, but wherever argon is extracted from the atmosphere for industrial usage it is advised to not concentrate it.
Also argon is not inert, it can combine with other elemnts, namely heavy weight metals like uranium.

 

[MarcusVatta]

Surface pressures are measured in Earth Atmospheres. Just like accelerations are measured in terms of earth gravity. The atmospheric pressure on the surface of this planet is 1.32 times the sea-level pressure on Earth.

Argon isn't poisonous, but it is heavier than O2, so it could suffocate you if the O2 couldn't reach the bottom of your lungs. If you weren't at sea level, then you'd probably be OK for a while until the Argon built up in your lungs. Most of the Argon would be in the lowest section of atmosphere, but it would still rise due to turbulence and weather patterns. So being in a low pressure system could be deadly.

I disagree. On Earth, the Atmosphere is a homogeneous mixture, and there's nothing to indicate that this planet would be any different (1.08 AU orbit, 0.5 Day rotation, 9degrees of axial tilt). Besides, it's not the weight of the gas that's important, but relative buoyancy. On Earth, a large concentration of Argon sinks because it is more dense than the surrounding air. On this planet, the Argon is part of the air, and wouldn't sink unless there's an usual concentration of it.
Long term, there might be health effects, and we don't know what the trace gasses are like (such as CO2) so those might cause problems, but I'd be willing to unlatch the helmet - err on the lab rats!

 

[CMDR AKIRA MASAKARI]

I disagree. On Earth, the Atmosphere is a homogeneous mixture, and there's nothing to indicate that this planet would be any different (1.08 AU orbit, 0.5 Day rotation, 9degrees of axial tilt). Besides, it's not the weight of the gas that's important, but relative buoyancy. On Earth, a large concentration of Argon sinks because it is more dense than the surrounding air. On this planet, the Argon is part of the air, and wouldn't sink unless there's an usual concentration of it.
Long term, there might be health effects, and we don't know what the trace gasses are like (such as CO2) so those might cause problems, but I'd be willing to unlatch the helmet - err on the lab rats!

From Wikipedia: Argon is used in the poultry industry to asphyxiate birds, either for mass culling following disease outbreaks, or as a means of slaughter more humane than the electric bath. Argon's relatively high density causes it to remain close to the ground during gassing
Although argon is non-toxic, it is 38% denser than air and is therefore considered a dangerous asphyxiant in closed areas. It is also difficult to detect because it is colorless, odorless, and tasteless. A 1994 incident in which a man was asphyxiated after entering an argon-filled section of oil pipe under construction in Alaska highlights the dangers of argon tank leakage in confined spaces, and emphasizes the need for proper use, storage and handling.^{[URL="https://en.wikipedia.org/wiki/Argon#cite_note-43"][SIZE=2][[/SIZE][SIZE=2]43[/SIZE][SIZE=2]][/SIZE][/URL]}
link: https://en.wikipedia.org/wiki/Argon

 

[Zelos1983]

So long as there is enough wind, the atmosphere should be homogenous?
Pressure and 5% less oxygen shouldn't be too much of a problem I believe.

Maybe we should send down a guy in a red shirt to check it out.

 

[MarcusVatta]

The key there is "Denser than Air" That means that Argon is denser than air on Earth, and displaces the air. On this planet, however, that density is evenly distributed throughout the lower atmosphere, meaning that Argon isn't going to displace the air - it is the air. This probably accounts for the increased atmospheric pressure, and would mean that Helium balloons would be much more buoyant, but it won't pool unless the local concentration of the gas exceeds the atmospheric average of 32%.

- - - Updated - - -

I just realized that Argon Fluoresces when ionized. The Aurora on this world would be AMAZING

 

[Ziljan]

but I'd be willing to unlatch the helmet - err on the lab rats!

I think you're assuming that the weather patterns would be similarly volatile as Earths, but on a planet with no volcanism and a day that is only 12 hours long, and gravity that is 1.32 times as high, it would be difficult to guess at the climate conditions let alone the weather. Homogeneity at this point is purely speculative. Would be nice if FD gave us scanners to check for this kind of detailed information.

One thing is likely however, that the differences between high temps and low temps would be less severe because they would heat for shorter periods and cool for shorter periods. This alone would have a dramatic impact on the climate and the weather since most places on the planet would be more stable like living along the coast here on Earth.

 

[MarcusVatta]

Looking at Jupiter, for example, a shorter day means more weather, not less. More coriolis force to put a twist on the Hadley cells, meaning more cyclonic weather. 9 degree axial tilt gives ok seasons, and the year is about the same length. The big missing piece is the oceanic distribution. Are there big oceans and big continents, like here, or some other pattern?

I think, though, we can assume the same or greater wind as, say, Mars, which has significant wind.

 

[Space Fan]

Should be fine. Note that while Nitrogen is an unreactive gas, it is not a noble gas as stated above.

You may need to breathe a little harder with 5% less Oxygen, but the Ar and N not an issue. The higher pressure will compensate somewhat for the lower percentage of oxygen.

 

[Yaffle]

37.7% of argon would make you choke and maybe make impossible to light a match, at least at sea level. That planet should be terraformed before removing suites. AFAIK there are techniques to extract argon from the atmosphere, maybe in a sci-fi setting they can be implemented on a planetary scale. To my knowledge it doesn't change the pitch of your voice tough.

- - - Updated - - -



Argon is way havier than oxygen, it would occupy the base of your lungs impeding CO2-O2 Exchange and you would die in matter of minutes.
In our atmosphere it's 0.92%, so its effect are negletable, but wherever argon is extracted from the atmosphere for industrial usage it is advised to not concentrate it.
Also argon is not inert, it can combine with other elemnts, namely heavy weight metals like uranium.

Not quite. Carbon Dioxide is even more dense than Argon, we seem to be able to breath that out quite effectively, and it's not sitting around our knees all the time. Unless, of course you're at a Deep Purple gig.

When you concentrate argon (or any inert gas) you are reducing the partial pressure of oxygen.

 

[Ziljan]

Looking at Jupiter, for example, a shorter day means more weather, not less. More coriolis force to put a twist on the Hadley cells, meaning more cyclonic weather. 9 degree axial tilt gives ok seasons, and the year is about the same length. The big missing piece is the oceanic distribution. Are there big oceans and big continents, like here, or some other pattern?

I think, though, we can assume the same or greater wind as, say, Mars, which has significant wind.

Jupiter is almost completely made of atmosphere and doesn't even rotate as a solid body, and more importantly it generates more heat than it recieves from the Sun. On Earth the coriolis deflection only impacts north-south velocities that are driven by convection from solar heating. But if the thermal gradient is less severe, then there will be less velocity to deflect. Ergo, less swirling and mixing of the atmosphere.

The same would be true for the currents in ocean. A reduced thermocline and reduced wind would lead to less strong ocean currents. Less mixing of nutrients, and less of a food base for ocean life.

 

[Zieman]

Slightly tangential, but as we're talking about atmospheres, I've been wondering about those Terraforming Candidates with high Ammonia -percent in their atmospheres (80+ %) - wouldn't that pose problems?

 

[Space Fan]

Equipartition of Energy: atmospheres don't separate out into distinct layers of gases according to molecular mass! - ours doesn't!

Why would Ar make you choke? It is inert.

See my post above.

This atmosphere would be breathable.

Note also that Oxygen is a diatomic molecule with molecular mass 2 x 16. Argon is monatomic, with atomic mass 40. It is not 'massively' heavier in the gaseous state.