Suppose we spend the money, and acually send astronauts to Mars. Suppose we acually have a colony-perhaps 50-100 people, who have decided to live there permanently. What will happen to those people’s bodies? WE eveolved on earth for our gravity of 1 G-so our hearst, muscles, and joints are capable of 70 years of life. Now, all of a sudden, you are living in a gravity field of ).35 G-all of a sudden your heart only needs to work at 1/3 capacity, and you can lift much larger items. Would this prolong your life? And, after 10-20 years of living on Mars, wouyld you be able to return to the earth? Would the stronger gravity kill you?
Proposals have been made to roof over some of the martian craters with glass, and pressurized the dome-the colonists could then farm the soil and live pretty normally-or would the UV radiation on Mars be too dangerous for them? :eek:
Actually, the majority of the work your heart does is to pump against peripheral vascular resistance–the resistance your body and blood vessels offer to flow–not gravity. Your heart only fights gravity pumping blood to your head, and that’s not much compared to the PVR. I’m not sure there would be all that tremendous a benefit to your heart, at least in terms of direct reduction of gravity.
Your venous system would benefit, especially your legs, since leg veins fight gravity all the way and depend on muscular activity, etc. No more varicose veins for our martian-dwelling adventurers.
With regards to muscles, however, living at 0.35 G’s would likely mean a loss of muscle mass all the way around and a hard time returning to earth where the increased gravity would feel opressive. (Muscle could be maintained by working out in your local Martian 24 hour fitness).
Here’s a interesting little article on the health effects of low-G/zero-G life for a potential Mars mission.
You mean “local Martian 24.5 hour fitness” 
Zev Steinhardt
Oh, here’s a weird one: would females still ovulate in 29-day cycles, or would they gradually shift to a Deimos/Phobos type ovarian cycle?
AFAIK The real problems would be dealing with the lack of water, and attacks by tribes of Green Men and roving bands of white apes.
I’m sure that John Carter can tell us more.
Solar ultra-violet radiation is not absorbed by upper-atmospheric ozone on Mars as it is on Earth (though our pollutants might eventually take care of that). Certainly if your goal is to permit people to walk around “outside” on Mars regularly while wearing normal clothing, and not spacesuits, then the glass shield over your crater will have to block all or nearly all high-energy radiation, including UV.
Which moon? You’ll have to pick, as the two periods are very different.
However, there is no known correspondence between our Moon’s orbital period and the human menstrual period. It’s just a coincidence, and only an approximate one at that. Most of Earth’s mammals have menstrual periods very different from 29 days. Our species just happens to have one in the vicinity.
For that matter, the gestation period of human pregnancy is about three-quarters of an Earth year. I doubt that that period will scale by a factor 1.9 for woman bearing children on Mars, just because they’re off their homeworld.
So basically I’m claiming that no, there would be no such shift.
Haven’t you seen Total Recal? Mars’s core is all ice.
So, withna roofed-over crater, and plenty of water! Lifeon Mars could be pretty good? Imagine the Martian Olympic games! Think of the high-jump and pole-vaulting records! Seriously: is there enough solar radiation on Mars to make growing earth-style crops (like potatoes, corn, wheat, apples, etc. feasible?)
And if we had some ham, we could have ham and eggs, if we had some eggs.
Here are a couple NASA links on the subject of colonizing Mars. I don’t think any of them claim life there will be a picnic. Note in particular this page about the water supply, which discusses the main difficulties without admitting that really, the whole enterprise is “dead in the water” if the problem isn’t solved.
Personally, I’m looking forward to the women’s volleyball games played in the lower gravity.
There’s a little more here on that. It looks workable for certain special crops, but not your common favorites, like for example apple trees and potato plants. I imagine the colonists’ diet will be quite limited compared to even prison food.
Also note that they probably won’t be raising cows or pigs on Mars, as they’re so much of a burden on the small, artificial ecosystem. (Not to mention: how do you schlep the beasts there in the first place?) So no hamburgers or barbecue in the Martian colony.
Like I said, it won’t be a picnic.
The effects would probably be similar to those from living in the space station. And we have actual records from that!
Without looking it up, here’s what I recall:
- muscles tend to atrophy, without gravity to work against. So they do regular exercises to maintain their muscles.
- bones tend to lose calcium (body figures it’s not needed in weightlessness?), so they take supplements with their food.
- sunburn/uv overexposure not a problem, since they are inside most of the time. In fact, they have to use sunlamps/take vitamin D supplements due to lack of natural sunlight.
Possibly, but we’re not sure yet. The water problem noted in Bytegeist’s links has some additional complications; it appears from the Spirit/Opportunity data that the available water would probably be better described as a brine, i.e. water packed with dissolved mineral salts. And you know how full of life the Dead Sea is, right?
And until we get a sample return mission, which will allow us to fully analyze the Martian soil in the best Earth-based labs, we won’t really know if the soil is rich enough to support plant life. It’s possible it’ll be fine; it’s also possible that only some plant life, like mosses, will be able to survive, at least in the near term. The hard radiation baking the ground has no doubt created some unpleasant chemical reactions and suffused the soil with chlorine compounds or other stuff that would need to be removed before large-scale agriculture could be performed.
Actually, that’s probably, only true for the first decade or so. It all depends, of course, on exactly how we attempt to colonize Mars.
The most likely scenerio, IMHO, is that we’re going to pick a spot like a crater, and then cover it with an inflatable dome. As a WAG, I’d say one about 100 yards in diameter. That would give the colonists room to spread out, and not feel too confined, and would enable them to practice square foot gardening to maximize food production. Now, there’s the issue of power production. Since we’re unlikely to find any fossil fuels on Mars, and geothermal is probably out, the two most logical sources are nuclear and solar power. Either one will work equally well. Mars doesn’t get as much sunlight as the Earth, but it also doesn’t have cloudy days like Earth does, so you’ll get as much juice out of the cells on Mars as you would on Earth. Pack along some full spectrum lights (which you’ll want to have anyway), and you can give whatever plants you bring along as much light as they need. Additionally, you can bring seeds and spores of other kinds of plants with you, that you can plant as the colony expands, this way you can avoid having a bland diet.
As for animals, well, in the case of mammals, that’s fairly easy. Once the colony reaches a certain size, you simply bring a couple of females of each species you want to establish and lots of frozen embryos. Birds would be a more difficult matter, since you’d need to bring several breeding pairs (as I don’t think that there’s any way of hibernating avian eggs).
I imagine, though, that the first animals people will want to bring along will be pets like cats and dogs. (And in a pinch, you can eat 'em.)
In a lot of ways, it would be easier to colonize the moon. Mars may not have a very hospitable environment. Specifically, it’d be very cold. Everything would have to be heated, big time. Since the atmosphere is thin, I imagine it wouldn’t be that bad (structures shed heat slower in thinner air), but it’d still be a pain.
The moon is close, it may have plenty of water, and without air it’s very energy efficient. Plus, there may be huge lava tubes which could theoretically be sealed and used to house thousands of colonists. These things may be as much as 1.5 kilometers wide, and have a room 10m thick, enough to protect from radiation and micrometeorites. Plus, the temperature would be constant. A big one might be sealed, pressurized, and house 50,000 people.
We know what the physiological effects would be for folks returning to Earth. But what about those who never return? Muscle atrophy, bone mass loss, etc., but would it matter if you never returned to a high-G environment? I presume colonists would automatically maintain whatever minimum level of muscle they needed to stand up and lift loads in their new environment (just by doing so). But would the bone loss be more of a problem? I can see their bones weakening to a level that would still be fine for supporting their bodies, but leaving them open to accidental breaks (from falls, etc.).
Well, a fall on Mars isn’t going to be nearly as rough as a fall on Earth, since the gravity is less. One of the things that will happen is people on Mars will be taller than they are on Earth. It might be because with less gravity they can grow more, but certainly, they’ll gain a bit of height since gravity won’t be compressing their spine as much.