hopefully there won't be any spiders
August 10, 2012 3:02 AM   Subscribe

Curiosity is making me curious. What would it feel like to stand on the surface of Mars? Let's say, first of all, it's without a space suit -- what would kill me first? The carbon dioxide in the atmosphere? The temperature? Then, if we found some way to breathe and function normally, what would it be like to be there? Would it be hot? Cold? Too windy to stand up? Paint a picture for me, if you can.
posted by fight or flight to Science & Nature (15 answers total) 6 users marked this as a favorite
Best answer: It would be very quiet, you would feel cold as the moisture on your skin evaporated in the thin Martian atmosphere, you would notice your vision start to narrow as you ran out of oxygen. Then you would lose consciousness and die.
posted by atrazine at 3:10 AM on August 10, 2012 [2 favorites]

Best answer: http://en.wikipedia.org/wiki/Climate_of_Mars

If you survived, you would experience the thrill of month-long planet-wide dust storms, and wildly fluctuating temperatures (though usually below freezing). You might even get to see Martian snow.
posted by kithrater at 3:38 AM on August 10, 2012

Best answer: Then, if we found some way to breathe and function normally, what would it be like to be there?

Mars' gravity is about 1/3 of Earth's, so one could have fun bouncing around. The length of the day is similar, so that wouldn't be jarring, but a Martian year is twice as long as an Earth year so time would probably seem to pass more slowly. The sun wouldn't appear as bright or large in the sky, no idea if that would bother some people.

NASA was worried about separation anxiety for astronauts leaving Earth and standing on the moon. Didn't happen. They're wondering whether it'll be a factor when sending people to Mars.
posted by Brandon Blatcher at 3:41 AM on August 10, 2012 [2 favorites]

Best answer: I think this is the more relevant link: Atmosphere of Mars. Ambient pressure being about 1/100 of that on earth, you'd be unconscious within 15 seconds and irreversibly dead within 90 seconds due to exposure to a near-vacuum.
posted by wutangclan at 3:47 AM on August 10, 2012 [1 favorite]

Best answer: Also, the dust blowing around on Mars may be extremely unpleasant, possibly leaving burn marks on the skin, not to mention being quite toxic. You'd really wish you'd packed that space suit, even if the atmosphere were breathable.
posted by pipeski at 4:05 AM on August 10, 2012 [1 favorite]

Best answer: In terms of the winds, although Martian speeds are very high, the extremely low air-pressure means that they'd have very little buffeting effect on your body.

Kim Stanley Robinson's Mars trilogy gives plenty of fictional but well researched accounts of the Martian surface, if you're look for an evocation of the experience. The books aren't scientifically impeccable, but they are exceptionally well done given the scope of their subject, and are convincing and evocative.
posted by howfar at 4:18 AM on August 10, 2012 [8 favorites]

Response by poster: Excellent answers all round, thank you! I can't get over the feeling of seeing those panoramic views coming back from the rovers. I will certainly be checking out Kim Stanley Robinson's work.
posted by fight or flight at 4:28 AM on August 10, 2012

Best answer: I came in to say that Kim Stanley Robinson wrote three books largely prdicated on these questions. You should check them out.
posted by OmieWise at 4:31 AM on August 10, 2012 [1 favorite]

Best answer: There was a similar discussion on reddit.com/r/askscience


It's a pretty cool nook of the internet with questions similar to yours, check it out!
posted by OuttaHere at 4:50 AM on August 10, 2012 [1 favorite]

Best answer: You would die from lack of oxygen before you would even start to be affected by too much CO2. In fact, I don't think an excess of CO2 in a low pressure atmosphere will kill you unless you have some susceptibility to it. There has been plenty of research on high pressure atmosphere but Mars would be a whole different ballgame. Although the atmosphere of Mars is mostly CO2, the concentration and pressure are not enough to cause the same problems as here on Earth.
posted by JJ86 at 5:56 AM on August 10, 2012

Best answer: I recall reading that at the peak summer time near the equator the surface can get as warm as 70F, provided that the sky isn't obscured by dust storms. However, because the atmosphere is so thin that temperature would only exist a few inches above the ground and it would rapidly feel closer to 40F. This was illuminating because at first I felt encouraged by that moderate temperature but atmospheric pressure makes the real difference. Strange as it seems, water would boil away on the surface due to low pressure.
posted by dgran at 6:18 AM on August 10, 2012

Best answer:
Every now and then, I spend time on Mars. I dig my naked toes into the fine, red-orange soil, watch how it clings to my skin -- and feel an incipient itch. The iron-rich dust is pretty alkaline. The air -- or lack of it -- also makes me itch. Pretty soon, I'll break out in what the locals call "vacuum rose," as the blood boils in capillaries beneath my skin, because the air on Mars is pretty nearly a vacuum.
Greg Bear
Why I Love Mars CNN
posted by bru at 6:44 AM on August 10, 2012

Response by poster: Here's an interesting data point from wikipedia via the Reddit thread OuttaHere mentioned:
Wikipedia says Mar's atmospheric pressure is 0.636 kPa. in comparison, Earth's atmospheric pressure is about 101 kPa. Mars therefore has 1/158 the atmospheric pressure of Earth.

"At NASA's Manned Spacecraft Center (now renamed Johnson Space Center) we had a test subject accidentally exposed to a near vacuum (less than 1 psi) [7 kPa] in an incident involving a leaking space suit in a vacuum chamber back in '65. He remained conscious for about 14 seconds, which is about the time it takes for O2 deprived blood to go from the lungs to the brain. The suit probably did not reach a hard vacuum, and we began repressurizing the chamber within 15 seconds. The subject regained consciousness at around 15,000 feet [4600 m] equivalent altitude. The subject later reported that he could feel and hear the air leaking out, and his last conscious memory was of the water on his tongue beginning to boil."

[..] So apparently 7 kPa isn't enough to stay conscious and 0.636 kPa wouldn't even be close.
So the sensations seem to be: extreme cold, dehydration, toxic razor-edged dust storms, blood boiling and suffocation.

Ah, the romance of space travel!
posted by fight or flight at 6:48 AM on August 10, 2012 [3 favorites]

Best answer: Of Kim Stanley Robinson's Mars trilogy (mentioned above by OmieWise) , only the first, "Red Mars," reflects Mars as it is today. I thought all three books were great reads.

I haven't yet read "Packing for Mars" by the wonderfully interesting Mary Roach, but I know from her related interviews that it is as much about the requisite space travel as it may be about being on Mars.

You could also try "The Case for Mars" by Bob Zubrin, a book advocating for a manned mission (colony?) in the near future. I presume he has answers to the questions of living there, but again, I haven't read it yet.
posted by Sunburnt at 8:14 AM on August 10, 2012

Best answer: FYI the atmospheric pressure on Mars is about the same as the atmospheric pressure on Earth at 28 miles above sea level, or about 150,000 feet.

By way of comparison, after extensive acclimatization, some people can survive and barely function for a short time at the altitude of Mt Everest, which is 5.5 miles altitude. So the pressure on Mars is like going 5X higher than Mt Everest.

Atmospheric pressure at Mt Everest is about 31 kPa whereas, as mentioned above, Mars is less than 1 kPa. In short, the atmospheric pressure is way closer to the vacuum of space (0 kPa) than anything we would consider even somewhat/barely breathable.

Another comparison--on Earth 28 miles altitude is about halfway to the Karman Line, normally considered the boundary of outer space. The Karman Line considered the boundary of space because it is the point at which the atmosphere becomes too thin for aeronautical purposes--any vehicle at this altitude would have to travel faster than orbital velocity in order to derive sufficient aerodynamic lift from the atmosphere to support itself. Or to put it another way, you could fly an airplane on Mars but only at a speed just below the orbital velocity you would need if it were an airless planet altogether.
posted by flug at 3:01 PM on August 10, 2012

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