lambda0 - 4/6/2007 8:28 AM According to Landis (NASA), the best place is ...Venus ! At 50 km altitude : - Atmospheric pressure is 1 bar - Temperature between 0° and 50°C - Plenty of solar energy but protection against the most dangerous radiations by the atmosphere - As the atmosphere is composed of CO2, a quite heavy gase, a balloon filed of oxygen and nitrogen would be in equilibrium, and a 1 or 2 km diameter balloon would easily carry a small city - Due to the rotation of the atmosphere, and by controling the latitude, it is possible to reproduce a day/night cycle similar to Earth - The atmosphere contains oxygen, carbon, sulfur, in fact many of the elements necessary for life At first sight, Venus seems to be a very hostile place (500°C on the surface, P=100 atmosphere), unless this thick atmosphere is considered as an ocean : Earth is also not so pleasant at 10000 m under the level of the sea. In fact, Venus may have many advantages compared to Mars... Interesting! What would be the "gravity" in such a "balloon"? What's your source of information?
lambda0 - 4/6/2007 8:28 AM According to Landis (NASA), the best place is ...Venus ! At 50 km altitude : - Atmospheric pressure is 1 bar - Temperature between 0° and 50°C - Plenty of solar energy but protection against the most dangerous radiations by the atmosphere - As the atmosphere is composed of CO2, a quite heavy gase, a balloon filed of oxygen and nitrogen would be in equilibrium, and a 1 or 2 km diameter balloon would easily carry a small city - Due to the rotation of the atmosphere, and by controling the latitude, it is possible to reproduce a day/night cycle similar to Earth - The atmosphere contains oxygen, carbon, sulfur, in fact many of the elements necessary for life At first sight, Venus seems to be a very hostile place (500°C on the surface, P=100 atmosphere), unless this thick atmosphere is considered as an ocean : Earth is also not so pleasant at 10000 m under the level of the sea. In fact, Venus may have many advantages compared to Mars...
Come on guys! Venus -- on the surface or in the atmosphere is incredibly hostile and dangerous environment. We need to realize that planets with atmosphere like Venus are actually far more hostile and dangerous than planets or moons with no atmosphere at all. Venus is probably a great potential candidate for terra forming but until that happens -- barring some stunning leaps in technology -- planting a colony on Venus, on the surface or in the atmosphere, would be criminal negligence at best and probably suicide as well. Surface temperature of over 752 degrees F, 90 times higher atmospheric pressure than Earth, sulfuric acid clouds, winds of 300 km per hour -- sounds like Hades to me. Read it and weep (from Wikipedia -- Venus Atmosphere.)
Venus has an extremely thick atmosphere, which consists mainly of carbon dioxide and a small amount of nitrogen. The pressure at the planet's surface is about 90 times that at Earth's surface—a pressure equivalent to that at a depth of 1 kilometer under Earth's oceans. The enormously CO2-rich atmosphere generates a strong greenhouse effect that raises the surface temperature to over 400 °C (752°F). This makes Venus' surface hotter than Mercury's, even though Venus is nearly twice as distant from the Sun and receives only 25% of the solar irradiance.
Studies have suggested that several billion years ago Venus' atmosphere was much more like Earth's than it is now, and that there were probably substantial quantities of liquid water on the surface, but a runaway greenhouse effect was caused by the evaporation of that original water, which generated a critical level of greenhouse gases in its atmosphere.[13] Venus is thus an extreme example of climate change, making it a useful tool in climate change studies.
Thermal inertia and the transfer of heat by winds in the lower atmosphere mean that the temperature of Venus' surface does not vary significantly between the night and day sides, despite the planet's extremely slow rotation. Winds at the surface are slow, moving at a few kilometers per hour, but because of the high density of the atmosphere at Venus' surface, they exert a significant amount of force against obstructions, and transport dust and small stones across the surface.[14] Above the dense CO2 layer are thick clouds consisting mainly of sulfur dioxide and sulfuric acid droplets. [15][16] These clouds reflect about 60% of the sunlight that falls on them back into space, and prevent the direct observation of Venus' surface in visible light. The permanent cloud cover means that although Venus is closer than Earth to the Sun, the Venusian surface is not as well heated or lit. In the absence of the greenhouse effect caused by the carbon dioxide in the atmosphere, the temperature at the surface of Venus would be quite similar to that on Earth. Strong 300 km/h winds at the cloud tops circle the planet about every four to five earth days.[17]
stargazer777 - 3/6/2007 11:35 PMI think that something along the lines of the O'Neill space habitats will ultimately prove to be the the solution of choice for off-world habitation, at least until we find or create another Earth-type planet.
I would think that by the time we can actually build and maintain something like that, we should be able to terraform a place like Mars. Terraforming would probably be easier than the space habitats. Has anyone read Rendevous with Rama"? It's a great read - I recommend it. Rama is an O'Neill-type space habitat. Fascinating read.
Actually, by the time we start assembling space craft and other large structures in space we will be half way home toward developing a space-based industrial infrastructure. Obtaining raw materials launched via mass drivers from the Moon or asteroids to a processing point -- at first probably one of the Lagrange points -- will be a second critical step. The others will come quickly. This will begin to happen within our lifetimes. Habitats are, ultimately, just very big space stations. If the bulk of the mass can be obtained this way that will go most of the way to making these ventures economically feasible. Initially at least, they don't have to have all the bells and whistles O'Neill imagined -- big lakes, forests, vast farms -- to be totally functional and very pleasant place to live and work for human colonists and their children.
We will reach this point long before we are in a position to begin significant terra forming of a planet. Additionally, I think terra forming on a planetary scale is going to prove to be far more difficult and far more complex than we imagine. The time line for meaningful improvements for planets like Mars or Venus could easily be centuries -- and that assumes no catastrophic set-backs. But, ultimately, only time will tell on these predictions.
Most any place in the solar system where there is a profit to be made you will eventually find human beings. Now, whether it's a good place to live or not is another matter. Eventual human colonization of the solar system will go where there's money to be made. 500 years ago, Central Florida was (by modern standards, at least) a miserable place to live and now I call it home--but it's a radically different place than it used to be centuries ago. The same will probably go for the solar system. :cool:
Most comets are travelling at something akin to 'ludicrous speed'. Good luck doing a rendezvous with that!
Titan is a very nice place and yes, you get that view of the rings. I'm selling land parcels to anyone interested. . .
What about colonies just out side the asteroid belt or even buried inside an asteroid?Ceres pretty much has just about everything you need and it's surface is supposedly mostly water ice.
Ceres is pre-stashed ocean in storage for Mars terraforming. Keep your appendages off please.
Quote from: Patchouli on 06/19/2009 07:14 pmWhat about colonies just out side the asteroid belt or even buried inside an asteroid?Ceres pretty much has just about everything you need and it's surface is supposedly mostly water ice.Ceres is pre-stashed ocean in storage for Mars terraforming. Keep your appendages off please.