re: While we are on the subject of alien life definitions
... Exobiology sounds better to me too.
BTW, imho all terrestrial planets while in their infancy had some similar compounds as asteroids and comets. Emphasis on some and time makes a big difference.
I'm one of those that believe that all terrestrial/protoplanets shared the same components and of course, H2O was one of them.
I'm only suggesting that additional H2O and amino acids were delivered by way of comets and asteroids in later years. Nope, nothing new, but I'm in total agreement with that one.