But how did they evolve?
Where all this water come from? -
A puzzle to be solved.
From comets? thought the scientists,
But there was a big catch:
The comets from the Neptune range
Our water did not match!
The outer solar system comets,
As far as one could find,
Contain much more heavenly water
Than our earthly kind.
So now new hope: the inner comets
Might yield the answer true,
And with Rosetta in position,
They waited, what'll ensue?
But Rosetta's first measurements
Left scientists abashed:
The data clearly showed,
The theory must be dashed!
Asteroids are the latest source
That helped the Earth beget.
Their water matches ours -
The Earth was always wet!...