Dad and I are watching an episode of "The Planets" called "Life". It started about 30 mins ago.
One thing we noticed is that as the search for non-Earth life began and matured, they were always looking for "earth-like" planets with "life as we know it".
I don't understand this. I mean, yes, we've found life here on earth that survives in extreme conditions (hydrothermal vents, salt beds, inside ice, etc), but we're still looking for "earth-like" planets with "life as we know it".
What I don't understand is, why can't alien forms of life have somehow evolved (even if remaining basic, simple, single-celled, etc) in places we would not expect at all, in conditions so extreme they are not found on earth?
Why can't some alien form of life have evolved to live on the gas planets like Jupiter and/or Saturn, or the ice-cold planets of deep space like Pluto, or even in the extreme heat conditions of planets like Mercury and Venus? Or what about possibly the craziest idea, a strange, alien form of life somehow evolving inside stars, like our sun and so on? Or what about life floating around space itself?
Sure, life as we know it requires liquid to survive, but does that mean all imaginable forms of life, and perhaps some unimaginable forms, require liquid? Does life chemistry really require a rocky, watery planet like earth to even happen? Is that really a legit assumption to make?
And it isn't just the conditions for life, but the forms of life we're looking for. It seems we assume that intelligent life would walk on two legs and have a somewhat recognizable body. Why? Couldn't intelligent life come in another form?
Is the reason we're having so much trouble finding life because even intelligent life billions of years ahead of us have not managed to get around the Universe fast enough to find us? Or is it simply because our "search terms" are way too limited and we're not allowing for possibilities that may seem counter-intuitive at first (life on worlds like Mercury, or Jupiter, or Pluto, or maybe life in stars, or just floating around space)?
What are your thoughts on this?