Survivability on hostile planets

[AssailantSponge]

I was curious as to what other people thought on different conditions of planets that could not support life. I know there are many variables, but what do you think would be minimally survivable conditions required to survive on a planet with nothing but your Earthly clothes and an air supply?

 

[eburacum45]

I was curious as to what other people thought on different conditions of planets that could not support life. I know there are many variables, but what do you think would be minimally survivable conditions required to survive on a planet with nothing but your Earthly clothes and an air supply?

As far as temperature goes, with the right clothes you could briefly survive on a planet with a temperature comparable to the maximum range of temperatures on Earth, that is from -60C to about 60C, but the hot end of such a range would be intolerable for any length of time. At least on a planet at the cold end of that range you could survive a little longer in a shelter. To survive indefinitely you'd probably need to have an ambient temperature between 0C and 40C.

Pressure is also very important. If the planet has a atmospheric pressure much below 200 millibars you will struggle to get enough oxygen, even with a facemask supplying pure oxygen. If you try to fill your lungs with oxygen in a low pressure environment your lungs will fill up like a balloon, and you won't be able to breathe out while wearing the mask. So in a low pressure environment you'll need a pressure suit.

In a high pressure environment you risk nitrogen narcosis, so your breathing mix will need to be something different to normal air. In addition a high pressure environment adds to your problems with heat balance; a hot, high pressure environment heats you up more quickly, and a cold high pressure environment cools you more quickly.

Hope this helps...

 

[StarRider1701]

...what do you think would be minimally survivable conditions required to survive on a planet with nothing but your Earthly clothes and an air supply?

You'd better hope you don't need an air supply, otherwise you won't last long. Let's say, for the moment, that you have a device that powers itself indefinately and can pull what you need from the hostile air and give you what you need. Living in a mask forever isn't fun, and you had better be able to make them out of the planet's materials or have a lot of them of very adjustable sizes. Also, are there poisons in the air that might be absorbed into the skin over the long term? If we can't breathe without help, I don't think I'd call that survivable in the long term.

Take a look around you! This Solar System is filled with places where we can't live without a considerable effort. If you are talking about only having the clothes on your back for environmental protection, then you've pretty much restricted yourself to Earth, or any planet very similar to Earth. As eb said, overall temps can vary a little, but not much. The same with atmospheric density and makeup. Since I think you might be leaning in that direction, NO, Mars is not livable. Too cold and not enough atmospheric pressure. You might as well be living on the Moon, except you've got a pesky atmosphere to contend with. Watch those sandstorms, they can be doozies! Seriously, it will take a similar effort to live on Mars as the Moon, except the moon is a lot closer and easier to get to.

So let's go build a Moon Base! Can't wait to get off this planet - except that I'm to dang old, they prolly wouldn't let me go.

 

[AssailantSponge]

Thanks for the info. Sorry I wasn't clear; I was only talking in the theoretical, meaning on other plausible planets instead of our solar system. If not for the unimaginable temperatures on other planets in our solar system causing your death, then solar radiation would do you off quickly I would think. But, if you're exposed to vacuum and no radiation from the Sun, say, behind the dark side of a celestial body, then the only way your body would be able to get rid of heat would be by radiation, right? And I wouldn't think that would be much, however I don't know much about these things. :shock:

 

[AssailantSponge]

Although, space IS much different than any planet...

 

[a_lost_packet_]

... But, if you're exposed to vacuum and no radiation from the Sun, say, behind the dark side of a celestial body, then the only way your body would be able to get rid of heat would be by radiation, right? And I wouldn't think that would be much, however I don't know much about these things. :shock:

Yes. Radiative heat transfer is the only way. There's no medium for conduction. But, your body would still, obviously, lose heat in that way. Eventually, it would become slightly warmer than absolute zero, in equilibrium with the average temperature in space. (It's not absolute zero due to background radiation.. but, close enough.)

How long that would take would be something one would have to calculate. I assume there are various equations with blackbody radiation that would come into play.

 

[JonClarke]

If you have a shelter to retreat to people have live and work at surprising extremes.

In Antarctica people have worked at below -80, in deserts above 50. These limits can be exceeded with heated or cooled suits. Maybe 60 dgrees and -100

Towns exist above 5000 m where the partial pressure of oxygen is only 106 mb. People can aclimatise to altitudes of up to 6000 m, where the partial pressure of oygen is only 95 mb. But people can't settle as children cannot be carried to term.

Saturation divers work below 500 m where the breathing gas is only 4% oxygen. However the pressure limits of human reproduction has not, not my knowledge, been explored.

 

[CAllenDoudna]

Without water you'll only last three or four days at best. When your supply of Earth food runs out (your body is likely to reject non-Earth food) you can get by for a couple of inactive weeks, my four-greats grandfather and his companions lasted 8 days on an island with no food but were so weak they could not stand and could only raise their hands when a ship finally passed by and rescued them. World War II experiments with American volunteers who wanted to avoid being drafted into the Army showed that well over 40 days could be endured and after three days your body adjusted and you no longer noticed hunger nor did you loose as much weight after the third day.

You can even survive in vacuum for a couple of minutes--part of that time you'll even be conscious. I predict one of the stunts our grandkids will be pulling will be to get their space cars running side by side and then with no spacesuit on climb out the airlock of one and jump to the other and scramble in the airlock all without a spacesuit to prove they're men and anybody who won't do that will be a wimp.

 

[AssailantSponge]

Again, thanks everyone for the information.
I have a very hard time believing that there is another Earth-like planet out there, because the conditions making Earth habitable are so amazingly fine- tuned that I can't seem to think another one exists. It's even placed in a perfect spot in the galactic neighborhood to help tremendously in humanity garnering knowledge of science, not to mention the fine tuning of the laws of physics, distances of the Sun, Jupiter, Moon, right chemistry etc. That seeming impossibility has manifested itself in me trying to figure out the limits of the human anatomy and maybe the theoretical conditions necessary for a human to survive. Environmentally controlled shelters on a celestial body in the outer reaches of a Sun like star could have enough levels of water ice for drinking and respiration if the water was shot with electricity, and the hydrogen could provide fuel. The problem comes with coming OUT of the shelter, because then, depending on the length of your excursion the level of resources needed would vary greatly, and everything supporting your body's function has to be light enough to carry, yet robust enough to survive any hostile conditions you would have to contend with.
In short, we should all be thankful that the Earth is a space shuttle of sorts that has all the resources we need.

 

[StarRider1701]

I have a very hard time believing that there is another Earth-like planet out there, because the conditions making Earth habitable are so amazingly fine- tuned that I can't seem to think another one exists.

There could be many other planets out there capable of supporting life. Consider the odds. There are at least one Billion (with a B) stars in our galaxy similar to our Sun. If only 1% of those have planets and only 1% of those have small, rocky planets and only 1% of those have small rocky planets within the habitable zone of its star then there could be 1,000 Earths out there.
So many people have this wierd notion that Earth is some kind of rarity in our Universe. But that just doesn't make sense, statistically or realistically.

In short, we should all be thankful that the Earth is a space shuttle of sorts that has all the resources we need.

Yes we should be thankful. BUT the resources of Earth are finite. We need to find ways to start using extra-terrestrial resources as soon as we practically can, beginning with a much better use of all that energy the Sun gives away every day!

 

[jim48]

StarRider knows what he's talking about. After all, he survived Operation Area 51 Freedom!

 

[AssailantSponge]

So many people have this wierd notion that Earth is some kind of rarity in our Universe. But that just doesn't make sense, statistically or realistically.

I find the evidence of everything on Earth to indicate that it is quite unique, although by no means am I trying to disrespect what you think.
Virtually everybody in scientific communities make a very stark leap in saying, "well, if prerequisite A, B, and C are met on a planet, then the planet will almost CERTAINLY have life." Having a planet in the habitable zone of a star by no means make it have life in the first place. It has to have so many things going for it, it's a statistical impossibility for life to occur without an intelligent force behind it. You could say, "if it has the right materials, temperatures, gravity, and protection needed for life, then it almost CERTAINLY have some of it's own." That's like telling me, "well, this would-be skyscraper has all the right materials here, and there's even enough rivets to hold the metal I-beams together. Oh, and look, there's plumbing and electrical wires over there ready to be installed. It MUST be able to create itself." But if there are no workers to put the skyscraper together, what exactly are you saying? That the skyscraper WILL put itself together? Go ahead and say that to a stranger, and they'll laugh at you. But that's what people are saying about life, and it's virtually overlooked.
Now, that's not to say I wouldn't want to see another planet like our own though. But you have to step back and look at all the assumptions you are putting in place.

 

[Sycamorefan]

I find the evidence of everything on Earth to indicate that it is quite unique

Granted, StarRyder1701 could be a bit optimistic when he thinks there are "1000" Earth- like Terrestrial planets in this galaxy, BUT that doesn't mean the logic behind his belief isn't mathmatically and statistically sound! I agree with his basic premise that out of 400 billion chances, there should be more than one Terrestrial planet out there like Earth in this Galaxy, and thats not even taking Exomoons into consideration!

Likewise, AssailantSponge on this Quote:

It has to have so many things going for it, it's a statistical impossibility for life to occur without an intelligent force behind it.

Even I must admit, I can't rule out the possibility of Intelligent design as a possible explanation for Earth, The Universe, or it's Physical laws! BUT; don't confuse that with saying that it is the only explanation! I just saying keep an open mind and lets see what Kepler has found in 2011!

BTW, I feel very fortunate to have a place like these Forums where people with intelligence and interests like My own can discuss these topics and better still, it's not a bunch of people echoing the same opinions!

 

[AssailantSponge]

Even I must admit, I can't rule out the possibility of Intelligent design as a possible explanation for Earth, The Universe, or it's Physical laws! BUT; don't confuse that with saying that it is the only explanation! I just saying keep an open mind and lets see what Kepler has found in 2011!

Thank you Sycamore fan! All I am trying to say is when it comes to science, let the evidence speak for itself unbiasedly.