Whenever we’re outside on a clear, starry night, our eyes are inexorably, almost irresistibly, drawn skyward, as if we can’t help ourselves from pondering and contemplating the great expanse of space that lies above us, separated only by our thin atmosphere. Yet within that atmosphere, many sights appear that often confound us: streaks of lights, sometimes flashing and sometimes steady, sometimes colored and sometimes white, frequently appearing to move at angles that make it difficult to know precisely what the nature of this object is or how far away it truly is from us. Most of these phenomena turn out to have mundane explanations, but for a few of them, their presence remains unexplained.

Could these hard-to-identify objects, normally called an unidentified aerial phenomenon (UAP) or an unidentified flying object (UFO), be signs of something beyond what modern science has the ability to explain? Could they even, potentially, be the result of activity by intelligent extraterrestrials? We shouldn’t let our imaginations run wild; we should figure out how to answer these questions scientifically. That’s what Stephen Johnson wants to know, as he inquires about the:

“ways in which we might scientifically evaluate UAP sightings (to the extent that such a project would be possible)… [is there] a way to think about thresholds that would have to be met in order for scientists to take these supposed phenomena seriously? What are some specific types of data we’d need, in your opinion, for scientists to reach a reasonable consensus that [any particular] sighting should be attributed to, if not extraterrestrials, a phenomenon with no known Earthly explanation?”

It’s a deep question to think about, and both believers and skeptics would be interested in the answer. Here’s how I’d approach it.

To read more, click here.