It has been a really long trip since we left our home planet. We have seen so many stellar systems but no planet was over 5 on our Viabilometer©... I was desperate until today ! My Viabilometer© is blinking ! We found one ! A planet with a score of 19.583 !
I am trying to establish a "planet viability scale" which can give a score (say from 0 to 20) reflecting the chances of a planet to be suitable for life. More precisely the potential of evolution of a life-form if I drop a microorganism on the planet.
For example :
- A planet with a score of 1/20 allows only days of survival for the microorganisms, thus they would not evolve a lot.
- A planet with a score of 10/20 allows some microorganisms to survive long enough to allows sub-aquatic vegetable and animal life-forms, but they would never go on earth and thus their evolution is limited.
- Finally, a planet with a score of 18/20 allows microorganisms to develop well and "quickly" enough to be able to escape their home planet and travel through stars.
In order to build this scale, I need some criteria that help evolution or curb it. What are the planet criteria that influence evolution of life ?
I know that distance from star, the type of star, presence and composition of the atmosphere, temperature are capital for example. Are there any others ? In what extent are they important ?