<So, the question is; did Earth contaminate the Solar system with life or was Earth contaminated from space. ;-)

I would have to say it most probably did -- if there is evidence out there. And this evidence could predate life on Earth by tens, even hundreds of millions of years, and still be considered ours -- Earth’s -- for a terrestrial form that might have escaped prior to the great impact that formed our Moon.

Hmm…. Interesting…. In other words, if such a scenario were the case, then ‘life’ that may have evolved on other planets would have had time to develop into beings like us.





Beings, certainly. Like us, doubtful. The scenario I was aiming for was of primitive life, barely multicellular. It took roughly 3,200,000,000 (3.2 billion) years from the advent of life for single-celled plants and animals on this planet to get the idea that colonies might be better (the amoebae still insist trees and whales are just a fad).

The Earth orbits within the habitable zone of the Solar system. It is here that life would be expected, simply because it is here that it is so easily found.

I suppose that such “habitable zones” can occur around other stars also.

The Habitable Zone is that region around any primary, such as a gas giant, brown dwarf, star, group of stars, or even an entire galaxy, where life is most likely to occur. The limiting factor to the theory, of course, is that we only have one the example of life from which to draw.

Thank you for the web sites they are great.

I measured the combined weight of free data available on the net a couple years ago, and the total measure was roughly “several tons.”
;^)

What if the evidence would indicate the existence of intelligent life on the planet, would we be comfortable while wondering about it? :-)



Not at all. We would be there.

You say we would be there? Could you elaborate on that.





If evidence of intelligent life on Mars existed, NASA would be over-funded to the point where they could just about build a bridge to the planet.

You had also asked about air pressure on Mars. That was determined with the Viking probes in the 70s, and each successful lander capable of measuring air pressure since.

Dan