New Mars Forums

At least 0.1 bar atmosphere will protect itself with ionosphere.

Do you have any evidence for this statement?  I'm quite interested in this area, so if you've seen any calculations, I'd appreciate a reference to them.

1.
http://en.wikipedia.org/wiki/Terraformi … _radiation

"However, recent scientific evidence suggest that just a thick enough atmosphere like Earth's is enough to create a shielding effect in the absence of a magnetosphere. In the past, Earth regularly had periods where the magnetosphere changed direction and collapsed for some time. Some scientists believe that in the ionosphere, a magnetic shielding was created almost instantly after the magnetosphere collapsed.[3], a principle that applies to Venus as well and would also be the case in every other planet or moon with a large enough atmosphere."

So I believe the ionosphere can provide the surface with radiation shielding even in the absence of a magnetic field, but I don't believe that the ionosphere can prevent itself being blown away by the solar wind in this situation.

the thin atmosphere of young Moon was retained for a few byr

Again, what makes you think this is true?

2.Celestia ED simulation.

Is Celestia ED something different from Celestia?  If not, then I don't believe that it models atmospheric evolution.

I believe the Moon had at atmosphere that was constantly replenished by volcanic activity for billions of years, but once the volcanic activity stopped, the atmosphere blew away in the solar wind (there are still traces left).

It is sufficient to hold atmosphere  and ionosphere will protect the atmosphere if it is sufficiently thick.
I suppose we should not worry.

But Mars is a counterexample to your theory.  It did have a thick atmosphere and its ionosphere did not protect it.

The ionosphere isn't something magic.  It is just gas atoms with electrons stripped away.  Without the magnetic field, they just blow away like normal gas atoms.  With the magnetic field, they are directed along the field lines and kept close to the planet. 

It is the magnetic field that is important.  If you have an atmosphere with a magnetic field, the solar wind will soon create an ionosphere.  But not vice versa.

We are ok with warmer temperatures in Canada.
In Canada we are thinking about a machine that makes co2 24/7  *lol*

Posted: Thu Jun 02, 2005 6:11 pm    Post subject:     

--------------------------------------------------------------------------------

<<Earth microbes may survive on Mars

Quote:
The team found that dormant spores of the bacterium had mostly died after five minutes of Martian UV exposure.

However, the bacteria were able to stay alive if they were shielded by just 1 millimetre of soil during the tests, which ran for up to 24 hours. >>

The whole issue of microbes on Mars or anywhere else in the galaxy is really moot. Microbial life is probably everywhere in the galaxy. They are incredibly hardy, able to exist under water at greater than boiling water temperatures, etc.  The cosmic issue is, what happens next?  Darwin's magic wand does not work until the conditions for life are very narrowly controlled. Thus, if you think (as all astronomers assume) that microbes + one billion years = animal life, you are very badly mistaken.

I am re-reading "Rare Earth: Why complex life is rare in the universe" by Ward & Brownlee.  This book should really be required reading by everyone on this forum. It points out the extremely tortuous route the creation of animal life took on Earth, guided along by an incredible series of accidents that are so unlikely to have occurred in just the sequence needed, that the Drake Equation (and Carl Sagan's million sentient civilizations in our galaxy) goes right out the widow.

This series of coincidenes is so incredible, it might even resusitate the religious arguement--although to be credible, it would have to be made by an atheist.

Heehee!

(Imagines the exo-biologist getting huuge fits over this.)

Hmmm edibility... How big are the chances they have the same aminoacid structure compared to human life, to begin with?

There are a few places on Earth where life is practically non-existent on the surface. One is probably the Atacamba (sic) Desert in Chile. Even there, you could dig down and probably hunt up a few microbes.

Rovers have a very slim chance of actually discovering life on Mars, since they only cover a limited area and can't really go underground.

There is very likely some life remaining on the Red Planet, but it's going to be underground. Two places come to mind:

1) Water occasionally wells to the surface on Mars. NASA pictures show it. Recent upwellings, not ancient ones. Look below the source of the upwellings.

2) Below the surface in caves where water still remains.

One general principle about 'life' in any form: If it ever existed, it is difficult to eliminate completely and totally. Assuming there was once life on Mars, to say that conditions have completely eliminated all remaining life is very unlikely. Life in itself is extremely adaptable, once it gains a foothold, and likely impossible to totally eradicate.

One way to look at it is this:

Imagine for a moment that tomorrow morning conditions on Earth changed to the exact conditions on Mars today. Of course...this would be the immediate end to civilization.  However, in a hundred years, could you say with any certainty that ALL life, right down to the last microbe, would be destroyed? It is much more likely that SOME limited forms of life would somehow survive. This could be the case on Mars, since it is apparent that conditions favoring life were somewhat more favorable in the past.  8)

<<I wanted to know if anyone could tell me where I can find surface temperatures for Mars during past epochs (any epoch will do except current conditions)? >>

I doubt this is known, although it could be found out by drilling into ice at the poles--the same way they do here on earth.  However, the sun was about 25% cooler millions of years ago--at the time Mars might have had liquid water on its surface. So the likelihood is that it is warmer now than it ever was.  That does not bode well for ever having had a lot of liquid water.

My question is whether a pressurized space suit would be needed at all. I think NASA needs to study shrink-wrap type suits. Such a suit would simply keep the body from expanding into space with shrink-wrap. Marshall T. Savage covers shrink-wrap type space suits in his book, The Millennial Project. A shrink-wrap suit would also allow more flexibility. Comparable to wearing a wet suit. Also, there are no joints in a shrink-wrap type suit. Joints have been a major problem for designing a Mars suit, because martian dust tends to get in and wear the joint out. It may seem surprising but such a suit may even have holes for the hands. Tests have been done where patients hands were exposed to complete vacuums. Apparently, no damage had occured, and the patients didn't feel any ill effects. There was a very controversal scene in 2001: A Space Odyssey, where one of the characters was exposed to space without his helmet on. While humans might not get away with this amount of exposure, as the fluid behind the eye would have likely pushed the eyes out, I beleive humans can expose their ams and legs to complete vacuums. For how long, I'm not sure. Does anyone have any more information on the vacuum exposure tests?

At least 0.1 bar atmosphere will protect itself with ionosphere.

Do you have any evidence for this statement?  I'm quite interested in this area, so if you've seen any calculations, I'd appreciate a reference to them.

the thin atmosphere of young Moon was retained for a few byr

Again, what makes you think this is true?

terraforming the Moon would not be feasible. First the Moon has a very inactive central core, which is part of the process for a liveable atmosphere to be made artificially or naturally.

How does an "inactive central core" prevent the maintenance of a "liveable atmosphere" ?

I would say terraforming the Moon is not a good idea. Never mind whether it can be done, it shouldn't be done. This is an airless world very close to the Earth, a highly developed settled planet with a giant thriving economy and a diverse biosphere. The Moon is needed for industrial processes that require vacuum and partial gravity, as well as interferometry telescopes that can image Earth size planets around other stars.

But Earth is deep within a gravity well, and the vacuum and viewing conditions are better at L5.  A terraformed moon would make a great base for exploiting the rest of the solar system.

Although a good idea, terraforming the Moon would not be feasible. First the Moon has a very inactive central core, which is part of the process for a liveable atmosphere to be made artificially or naturally.

   A more feasible appraoch would be to be facilities like is currently being built in Englang, I believe the project is called New Eden. What the project is is a combination Bio-Sphere/greenhouse.
 
   What could be done on the Moon could be done two fold - One Earth soil
with all the microbes that make up fertile soil would be sent to the moon, where do to Photosynthesis the foliage planted in the soil brought from Earth would create condensation on the glass window or thick plexiglass
panels that would run into gutters where the water would then be collected and used to irrigate the foliage and other needs.

  The second approach would be to have the same layout as above but instead of using Earth soil, Moon soil would be used. Although the result at first would be very dusty after a few light sprinklings of water to keep the dust down fertilizers could be added to enrich the Moon soil in an attempt to sustain the foliage.

  A good way to test this affect is too find an old baseball diamond that has a dirt infield, drag the infield until the top layer is a dusty layer that when you walk on it, everytime you step will result in a small puff of dust or microsoil to gush from where your foot was placed.