The Principle of Contingent Causation: The Impossibility of Infinite Regress.

[GrandizerII]

As for the universe. If you believe that the universe can only be one way, then that's logically fine, but be aware that this probably means you hold to an extreme view on modality. Because it goes against intuition to say it is not possible that our planet could have been one mile closer or further away from the sun (for example).

Actually, every Fourth of July the planet spends the next six months drawing 3.1 million miles closer to the sun, and just after New Year's Day it starts crawling back out again. It is not possible for out planet to be very much different than this, simply because it wouldn't be "our" planet, in that case, would it?  This would be the planet of a different species adapted to those conditions.

My fault for the incomplete wording. I meant at any point in time, whatever the actual position of the Earth is relative to the Sun, it could have been possible for that position to be different from what it actually is at that point in time.

Do you agree with the above?

You're right to suggest that at some point, counterfactuals reasonably cease to be close enough in resemblance to the actual thing under question, so that they should no longer be counted as counterfactuals. But putting that aside, if this universe could have been different in some way, even in a slightly different way, then it would be hard to make the argument for it being necessary, would it? If the universe, as it is actually, could have not existed, then you could still make the case for it being a brute fact, but it just wouldn't be a necessary brute fact (by definition).