habitable neighor planets

What if mars and Venus were always habitable?
This would not have ben determined untill the mid sixties when the mariner probes were sent.
How would that knowledge have effected the space race and Russia US relations?
Would the Vietnam war have happened, would we be at peace with the commies or waged war offplanet?
 
I don't see that happening with a post 1900 POD :p

Edit: The outcome would be post 1900 so I see your point.
 
You should read The Lords of Creation series by S. M. Stirling. The Sky People is about a habitable jungle Venus, In the Courts of the Crimson Kings is about a habitable desert-highlands Mars. The POD would actually be before the 1960s, such as when microwave tests are used to determine if oxygen is present on Mars or Venus. By the 1930s and 1940s there will be a few scientific divergences, and the scientific community and perhaps science fiction community will be in a better place regarding hypothetical habitable neighbors. Stirling conjectured that with these early discoveries, right after WW2 the US and USSR get started building rockets with the goal of getting to these other planets to see if the presence of oxygen means that there is life. Both sides don't waste a decade or so muddling around with various technologies and getting nothing substantial done. First satellite launched by 1950, first interplanetary probes, atmospheric or otherwise, observe Venus and Mars in the early 1960s. When life is discovered, that gives both sides a major motivation to get people there, and before you know it there's a moon landing, a moon base shortly thereafter, the construction of space stations, nuclear rockets, etc. etc.
 
I would imagine a sustained effort to set foot on them, so a more advanced space program.

I assume you mean they are in a state habitable for us, but lacking their own sapient life? If they did turn out to have comparable societies to us then that just creates many more questions!
 
Life forms

Mars has human like intelagent creatures with B.C tecnology they are about 4feet tall .
Venus has only animal life mostly deep jungle continuos cloud cover
 
This goes in the ASB thread: OTL Venus is too close to the sun to avoid a runaway greenhouse effect, and Mars is too small to hold onto enough of it's atmosphere long enough for advanced life-forms to develop. You'd need a larger Mars - not sure a smaller Venus would work, perhaps one with a really large moon to strip away excess atmosphere? And I'm not sure that even the slight changes in Earth's movement around the sun caused by a differently sized Mars and Venus wouldn't be enough to butterfly humanity out of existence.

"The Lords of Creation" is an ASB scenario - Mars and Venus are inhabitable due to some ancient and on-going intervention by offstage god-like aliens.

(Not that I don't enjoy a good ASB alternate-physics thread, of course. I found Garfinkle's Celestial Matters a hoot.)

Bruce
 
All you need is a more mercury like mars, with a strong magnetic field to hole the atmosphere, and give venus a weaker one, that should work...or some really tall mountains.
 
What if...

If its ASB, then how about a POD of billions of years beforehand? Go back to the beginning of the solar system. Mars gets a little more mass (say whatever event formed the asteroid belt didn't happen, or perhaps some of the mass that went into it was attracted by proto-Mars, thus making it larger and able to hold more atmosphere through gravity.) and Venus could have been formed closer to Earth in the Sun's habitable zone and a bit further from the Sun? Could that be considered to be viable?
 
If its ASB, then how about a POD of billions of years beforehand? Go back to the beginning of the solar system. Mars gets a little more mass (say whatever event formed the asteroid belt didn't happen, or perhaps some of the mass that went into it was attracted by proto-Mars, thus making it larger and able to hold more atmosphere through gravity.) and Venus could have been formed closer to Earth in the Sun's habitable zone and a bit further from the Sun? Could that be considered to be viable?

Its still ASB.

But thats no reason not to discuss.
 
This goes in the ASB thread: OTL Venus is too close to the sun to avoid a runaway greenhouse effect,
Bruce

In fact is the atmosphere what makes of Venus hell not its proximity to the sun. There are studies that indicate that its temperature could be very similar to that of the earth with another type of atmosphere.

I think that the problem with this thread is that, we don´t need habitable planets but a more suitable for terraforming. And, yeah, OK, that´s an old POD but I do not think that influenced Earth history until mid XIX

 
Mars was habitable

By evry indacation from our probes mars had liquid water at one time so it is very pobable that at one point in time life was possable there. As far as Venus goes I don't know but I think a different more reflective atmosphere could make a difference.
 
SavageDays said:
say whatever event formed the asteroid belt didn't happen

The 'event' is the existence of Jupiter and not having him in the solar system would make alter the development of planets in quite some way. All up front, the frequency of asteroid/comet impacts might go up by several magnitudes (just imagine stuff like the cretaceous impact happening repeatedly over the course of a few million years)

or perhaps some of the mass that went into it was attracted by proto-Mars, thus making it larger and able to hold more atmosphere through gravity.

Even all of the asteroid belt won't add that much mass at all (they'd contribute about 1% of extra matter to Mars) although a somewhat sizeable moon (for which that mass might suffice) could do the trick 8on enever knows what those tidal effects are good for :eek:
 
Does Venus's extremely slow rotation have anything to do with it's extreme heat?

Yes its the primary cause! And Venus's rotation is a result of its proximity to the sun. Mars has a better chance but you'll need more than just the asteroid belt to get Mars up to mass.
 
Venus

The rotation is not related to the distance from the sun. Both Mercury and earth rotate faster. Final rotational speed of a planet is random, largely induced by the mechanics of the last great impactor during planetary accretion. So a Venus that rotates faster, even in about 24 hours like earth and mars is feasible. But the POD almost has to be ca. 4.5 Billion years ago.

An impactor large enough to change the rate of rotation significantly would blow away much of the atmosphere, and melt the crust for a significant depth. It will take a while for the crust to cool and such. Not likely to result in a habitable world anytime soon. So a recent impact still won't work.

Even if you make the rotation reasonable, Venus is probably still going to be prone to a runaway greenhouse, unless the atmosphere is thinner than earth's, which again makes habitability unlikely.

Also, Turtledove wrote a book about Minerva, a habitable 'Mars' which was larger. Again, the POD is primordial (and so earth should be different too, really).
 
Following the same logic, could you imagine a slower-rotating Mars getting a thicker atmosphere, possibly a habitable one?

No expertise here, so disregard my question if it's physics.n00bish.
 
No

That won't help... Mars just needs to be bigger. Bigger initial volatile inventory, more gravity to hold what it has, more magnetic field to prevent solar wind from eroding the uppermost atmosphere.
 
let us assume Venus and Mars are just habitable for Humans
(like Venus rotate 24 hours (not 240 days) and Mars is more massive)

wat inpact on Cold War Space Programs ?

after the fist space probe discover that the planets are habitable
it change political decisions
in OTL as probe show Mars look more like Moon and Venus is a Hell
intrest for Manned fights to there wend to Zero


means the Moonrace is only first step in Space Race
who reach first the Planets will become major goal in Space Race

in U.S. Politican change goal to the planets
NASA start Post Saturn-V booster development
with 1000000 pound (453 metric tons) Payload

one proposal were Philip Bono ROMBUS (Reusable !)
see
http://www.astronautix.com/lvs/rombus.htm
ROMBUS can be used as mainhardware for Deep Space Mission
http://www.astronautix.com/craft/proelena.htm
http://www.astronautix.com/craft/proeimos.htm
even as intercontinental troop transporter or Passengers flights
http://www.astronautix.com/lvs/ithacus.htm
http://www.astronautix.com/lvs/pegvtovl.htm

with change goal in Space Race in 1964
the New Booster are ready around 1974
so the U.S. First Mars Mission can land on 4 juli 1976
a nice nice gift for 200 year celebration of USA ...
 
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