Solar System

I think water, our atmosphere the inclination etc is more important than temperature for the existence of life.

The temperature can be controlled by evaporation of water. At some stage earth may have been closer to the sun or more energy were coming from the sun and the earth was covered by a permanent cloud cover. The situation may have changed slowly until the cloud cover were not sustainable and the clouds collapsed in a short period of time.

I am always wondering if silicon based life (little green men) will be possible in different circumstances. (silicon is close to carbon on the periodic table). Maybe not.

Thankyou that has really helped.

Temperature is just one of the factors, but it's not the only one. Check out the following link to read about how even on Earth, there are organisms that can thrive in conditions that would be lethal to humans. It might give you a clue or two as to how life many develop and evolve on planets with environmental conditions totally unlike ours.

http://en.wikipedia.org/wiki/Extremophiles

With the millions of galaxies and the billions of stars within them, many people believe that somewhere out there other life may exist. Where we would fit in the equation of advancement may never be known. We would have to meet them and compare notes. That would tell us whether or not we are on the Einstein side of the equation or just slightly above the village idiot