It's absurd - and rather arrogant - to assume that earth holds the only forms of life in the universe. (I almost said "intelligent life", then I remembered reality TV and couldn't keep a straight face)
And it is possible that technologies and sciences we don't yet know about exist that permit travel from other planets to Earth.
That said, I'm nowhere near convinced that what advanced alien societies really want is a farmer's colonoscopy.
(To clarify, but in brackets and a bit down because it would kinda dilute the punchline otherwise, I'm convinced that there is intelligent life elsewhere in the universe; it's mathematically almost certain. But I'm still on the fence as to whether they've actually visited Earth. It would be nice, though, wouldn't it?)
And it is possible that technologies and sciences we don't yet know about exist that permit travel from other planets to Earth.
That said, I'm nowhere near convinced that what advanced alien societies really want is a farmer's colonoscopy.
(To clarify, but in brackets and a bit down because it would kinda dilute the punchline otherwise, I'm convinced that there is intelligent life elsewhere in the universe; it's mathematically almost certain. But I'm still on the fence as to whether they've actually visited Earth. It would be nice, though, wouldn't it?)