What if Jesus had failed?

[Sword of Christ]

You're describing skepticism moreso than atheism.

I think you'll find it's the same thing, though perhaps atheism is slightly more than skepticism.

The skeptic does not automatically reject every possible explanation for an event or occurrence. But he is likely to expect the explanation to be the most likely one, given past experiences and explanations. As Minimalist pointed out, if the vast majority of UFO sightings have proven to be something other than a UFO (as well as nothing particularly out of the ordinary), it's likely that the rest have a similar explanation.

Like I said 95% are naturally explainable and 5% are likely to be unmanned probes. They could be something else but that explanation would seem like the most reasonable. Bear in mind these objects are tracked on radar and are seen by reputable sources. We're talking professional trained pilots and even the crew of the Apollo first mission to land on the moon these guys aren't crackpots or something. It seems likely these things have been appearing for thousands of years ass reports of them go way way back.