Comment #418162 by Sally Luxmoore:

We are so lucky to be living now.

I couldn't agree more, when one compares our state of understanding of the universe now with that of previous centuries, we are indeed fortunate to be living now. On the other hand, I am sometimes dismayed by the fact that there are going to so many mind-bogglingly wonderful things discovered in the future (e.g. extraterrestrial life?) that I will never know about. Curse these mortal bodies!

SteveN
P.S. I fall firmly on the 'life does not have to resemble our sort of life' side of the fence. Statements such as "For instance, while visible and infrared wavelengths are important for life and processes such as photosynthesis, ultraviolet and X-rays are harmful.", especially from someone working in the field, strikes me as very narrow-minded. There may be beings sitting in their pools of liquid methane saying "For instance, while visible and ultragamma wavelengths are important for life and processes such as radiosynthesis, infraviolet and radio-rays are harmful."

As Richard has often said, all it takes for life to get going is the accidental emergence of a molecule (or even non-molecular pattern?) that has the property of self-replication. It would be ridiculous at this stage of our knowledge to claim that such an entity can only appear in a liquid water environment.