As David Hume discovered to his chargin, by his skeptical criteria there can be no scientific evidence that asteroids have and do hit the earth. The difficulty is not merely confined to the problems to do with verifying any non-repeatable past phenomenon which obviously cannot replicated, you cannot "experimentally" replicate the Cambrian Explosion.
The problem is that asteroids continue to hit the earth today, but we have absolutely no means of controlling when and where they strike the earth. So while we can be confident in our assertion that "asteroids occasionally hit the earth", the method of proof or evidence for this claim is baffling. In some sense we can "experiment" for it by trying to set up space telescopes to detect it, but that is the limit of our powers to detect and experiment. We can't actually produce an asteroid, nor can we actually predict at regular intervals when an asteroid will hit the earth. We can just watch and wait.
We can just be sure that it will hit, but it's occurrence comes, as the good book says, like a thief in the night.
And yet, despite our inability to actively experiment or produce the phenomenon, we consider both the proposition that asteroids have hit the earth and the continued bombard of the earth by future asteroids to be a well-established scientitic fact. Yet how could this be justified?
With good reason did Hume refuse to answer this objection when his detractors raised it against the skeptical epistemology he was busy wielding against religion.
This suggests an interesting analogy between asteroids and miracles.
1) Most of us have only the testimonial of others that asteroids have hit the earth.
2) Only rare individuals have experienced an asteroid event for themselves.
3) While we expect it to happen again we can't control when it happens next.
The exact same point applies to the occurrence of miracles.