tealeebee
Considering that there is a small atmosphere on Mars, then atmospheric pressure decreases with higher altitude and increases with lower altitude much like the "sea level" pressure on earth. At what depth under the surface of Mars would the pressure of gas mixtures in the atmosphere be equal to the "sea level" pressure on earth?
Do you mean if you dug a deep hole?

Arthur
Velocity
i don't know the exact number but i'd put it at 40,000ft down maybe... mars only has 30,000ft of atmosphere i think; that number is assuming that the density of air on mars is equal to that on earth
rethinker
QUOTE (adoucette+May 6 2007, 10:03 PM)
Do you mean if you dug a deep hole?

Arthur

No I think he was saying if you drug a scientest what would be the answer
tealeebee
thank you for your serious replies and one stoned-out dude on a Sunday night, too. Enjoy yourself. Here is a little more in depth explanation of the question:

Dig a deep hole, asked Arthur? Well, perhaps it already exists in the form of caves or channels.

Regarding the Earth related figures from Velocity, of course, Mars is not the same, but rather, much less dense. This also brings issues such as the plate stabiliies, mantel thickness and core size and temperature into the equation if one must go very, very deep.

There are two reasons that I have posed this question.

First, if it is feasible to reach a point where atmospheric pressure is at least increased as compared to surface pressure, then it will be at that depth where less structural stress will be placed on artificial environments that are built on Mars for habitation by humans.

The second requires greater calculation because it entails location a sector with atmospheric presssure that might have been similar to the atmospheric pressure on Mars when, 3.5 billion or so years ago, water was present on the surface and life might have possibly developed. If Mars evolved slowly, gradually losing surface water and atmosphere, rather than these being lost due to some cataclysmic event, then organisms might also have evolved gradually to adapt to subsurface conditions, yet still, to those that would have been most similar to their original surface environment. Figuring the variables into this theory would give a range beneath the surface where organisms might most likely have survived.
QUOTE
First, if it is feasible to reach a point where atmospheric pressure is at least increased as compared to surface pressure, then it will be at that depth where less structural stress will be placed on artificial environments that are built on Mars for habitation by humans

Well in that case, stop digging.

The atmospheric pressure on Mars is ~ 1% that of Earth.

Wouldn't matter how far you dug down (of followed a cavern), the pressure wouldn't increase sufficiently to make up for the effort of going down.

The pressure differential isn't that big a problem and we don't have to pressurize the inside to the level of Earth at sea level, as we (and most living things) do fine at lower pressures, particularly if we simply increase the partial pressure of O2 a bit.

Arthur
lengould
Agreed. No way to go deep enough to make any difference, starting at 0.01 bar. eg earth's atmosphere doesn't get that low until altitude 30 km Concepts and Approaches for Mars Exploration and the reduced gravity of Mars would require a deeper excavation than that (and at some point the mass above will start to neutralize the gravitational effect). Considering that the deepest mines mankind has developed in the friendly environment of earth is perhaps 8 km (I think gold mines in S. Africa), it seems like a highly unlikely approach, esp. considering that all that is needed is to seal and pressurize an excavation just below the surface.
Kid
hey i got some hmwk from my auto teach on what affects atmospheric pressure.. Anyone please?
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