Page: | 1 | 2 | 3 |
Gravity may also be too high. This would again make it obviously hardly practical to live on the surface for long, as well as causing severe health problems such as articulations wearing out very fast because of friction.
Is temperature adapted? Extreme temperatures shall force inhabitants to wear adequate combinations in order to regulate internal temperature. If it is very low, people will also have to deal with snow and ice as lighter elements become solid. If it is very high, the atmosphere may be filled with gases such as vapor rendering the air totally opaque and travel impractical even with infrared devices. This is by far one of the most severe practical issues to be dealt with.
Is the atmosphere adapted? There are several issues to be discussed, of which we will expose the most important. Of course there is one matter about whether the air is breathable or not. This is not limited to basic chemical composition, that is, as a mix of more basic gases. There may also be too much dust in suspension, or small micro-organisms dangerous or lethal for health. It may also be too hot or too cold to be breathed. In those cases, it may be enough to just wear some kind of mask and to carry a reserve or generator of breathable air.
But there are other matters. Too light or otherwise inadequate atmospheres may fail to successfully filter deadly radiations, which must be blocked in any other way. Again, the most obvious way is the classical hermetic combination, but there might be other solutions available, such as an orbital screen deflecting heavy radiations, electro-magnetic pulses being affected by intense magnetic fields, for example.
Also, winds may be far too strong for life to be practical, and even for sorties at all. In such cases the only option might be to live inside installations devised to resist such strong winds, and to restrict sorties to vehicles. It shall finally be mentionned that winds somewhat regulate temperature on the surface, so if they aren't strong enough, they may restrict the viable locations on the surface.
Is the surface adapted? If entirely covered by a huge ocean, one may doubt it. Solid ground must be either found or built. One classical option is to live on the bottom of the ocean, in underwater installations. One may also live in overseas submarine or maybe even air ships stations. Other conditions may render the ground impractical, such as seismic or volcanic activity.
There are many other issues which could be enumerated. I suggest, when you build viability criterias for any planet, that you attempt to make it as unviable as possible because in real contexts, this is how it will be.
Next: How to make a planet as viable as possible? We would obviously have to transform it in order to reduce any factor that would make it unviable, and to regulate those changes as needed. This is a generalization of terraformation.
The very first matter shall be gravity. Usually, one will look for a massive enough planet instead of attempting any transformation, but gravity alteration shall become possible in advanced contexts. My "technological referrer" suggests it shall be easy to generate an intense artificial gravitic field at the core of a planet in order to raise it, but the opposite is much trickier to say the least.
Then temperature. This issue comes along with atmosphere as the latter contribute to hold and regulate the former, while the former may help to generate the latter. To put it simple, on planets with no atmosphere, it has been suggested to heat it artificially with nuclear bombs, which shall allow an atmosphere to appear where context allows.