The Earth has all the known elements that exist in the Universe. From these elements life has been created and developed. So any life in the Universe would also be made of the same elements and would have the same restrictions for existence, and would need similar environmental conditions. This is not to say that there would not be different looking lifeforms if these conditions did exist. But the limitation of the required elements is the reason we don't have flaming Venusian lifeforms running around the Universe, or green skinned maidens from mars crying out "show me more of this Earth thing you call kissing" etc etc.
You are probably correct, W&F. Planet Earth probably does have some of every known element that exists within our universe. I would suggest however that they are only the known elements. That can possibly be said at present but it is likely that we have not yet identified all elements on earth. Ununpentium, atomic number 115, was discovered by some Swedish scientists in 2013. Haven't yet found out yet if Ununpentium exists anywhere else, other than on Earth.
However, we are still discovering this, that and the next thing. This means that we are still not sure that we know every single element on Planet Earth and it has to be said that at present our universe only has in it the things that we know about and can therefore identify, therefore there is quite possibly a lot more to be found out there and a lot more to be learnt. There is no proof to suggest otherwise - at present.
This suggests that there is possibly a lot more to discover. Will this mean aliens in the solar system, the universe - or somewhere that has yet to be discovered?
Edited by George., 21 October 2018 - 08:43 PM.