NASA-UAP-D023, Interview Excerpt with Astronaut Gordon Cooper, 1962

You expressed interest at one time in unidentified flying objects, the feeling that there might be something to all these stories. Do you still feel that way? Well, I feel that there have been a large number of fairly well qualified, or exceptionally well qualified, I should say, people who have seen objects that have not had any really logical explanation other than this. I think that maybe, in fact, each and every one of them does have an explanation. But I think that there are so many possibilities, so many thousands of possibilities of other planets out somewhere in the universe that would have a livable atmosphere, that I would hate to rule out the possibility that maybe there are people or some type of human life on some of these. And if this is the case, then it's not too unfeasible to think that perhaps some of these objects might have been something of this type. You don't think that the comparatively short step out into space that the Mercury flight will take you on is far enough out to make any observations in this area? No, I think we're still at a fairly low order of getting out into space when you regard, when you speak of space and being millions of miles involved. And we're only getting out a hundred miles or so. What about the so-called Glenn effect? Gordo, the snowflakes, the fireflies, now both Charron and Carpenter seem to feel that it's frost of some nature off of the capsule. But apparently Glenn still sort of casts doubt on that theory.