No we don't -- we only know that the tiny fraction of the Moon's superficial surface we've examined turns out not to be cheesy. For all we know, the other 99.99+% of it might have a very high cheese content. The most parsimonious *theory*, however, is that the rest of the Moon is reasonably similar to what we've managed to personally examine -- but there are no guarantees that we won't find some really big surprises (cheese or otherwise) as we examine more of it.
It is, in fact, highly unscientific to say that we have "PROVEN" that the rest of the Moon necessarily is like what we have looked at so far. As even your own flawed example illustrates nicely, this is why science does not deal in "proofs". All conclusions are open to revision by further discoveries or ways of looking at the known evidence.
For a nice but short introduction to this issue of epistemology, read 29 Evidences for Macroevolution: Scientific Proof? . A longer discussion can be found at Evolution is a Fact and a Theory , and a broader examination at Evolution and Philosophy: An Introduction .
There is NO PROOF of the THEORY of evolution.
Of course not, just as there is "NO PROOF" that there are any such things as atoms. There is, however, very strong evidence for the existence of atoms, just as there is very strong evidence for evolution.
Even Darwin spoke to "micro" evolution, not "macro" evolution.
Wrong. Try reading The Origin of Species sometime.
It's, (evolution), a THEORY.
Read the above "fact and theory" link to understand where you're making your error.
Of course no "serious" "scientist" will ever disprove that THEORY, if they are not allowed to look.
But they are allowed to look, so your point is... bizarre.
Just how far have we come in scientific method, and honest exploration, in "science" from Galileo's time?
Ahem -- need I point out that in Galileo's time, as in the current anti-evolution flap, it's the *religious* community that's trying to suppress the scientific discovery?