Pondering life on Mars

Here is a nice article by Sir Patrick Moore that appeared in the New York Times online. He talks about how Mars, if we find evidence of life, will prove that life will exist in the universe when it can--assuming, as well, that Mars at some point has had suitable conditions for life. If we don't find life, we'll still be wondering. It's all pretty neat to think about. I'm not sure if people will be able to read the article unless they're subscribed, so in case you can't access it, here's an excerpt:

We may be virtually certain that many planets moving around other stars are similar to Earth in size and mass, and that many of their parent stars are of a solar type; after all, our Sun is a very ordinary star. It follows that in the galaxy there are vast numbers of planets that are suitable for life of the kind we can understand – that is to say, carbon-based life. (I do not propose here to discuss truly alien life-forms; that would lead into totally uncharted waters!) The vital question, then, is this: will life automatically appear upon a world where conditions are tolerable, and will it then develop as far as its environment permits? If we could find just one world that does support life, we would be entitled to claim that life must be widespread all over the universe. And to me, it seems that the clue may be given to us by our near neighbor, the red planet Mars.

(Sir Patrick Moore, "Is Life Elsewhere?" New York Times Online, March 25, 2007)