Looks like a hole punch from a 3 ring binder to me, but through plastic and very enlarged.

[Diameter is slightly over 5mm on the negative, but it's not a hole; there's film grain visible. Note also that the edges are sharp, but the treeline is blurry. As others have mentioned, this points to a processing artifact. - tterrace]

Those two bikes sport the more stable of the two types of stands common then. One could even use a bike so equipped as a kind of exercycle, since the rear wheel was held entirely off the ground (no puns, please). Unfortunately, the catch that held the stand out of the way while one was in motion frequently wore out, causing the stand to drag behind the bike and produce a grating noise dear to little boys but the bane of every mother in the neighborhood.

So is EW3 correct (UFO)? Or Tobacconist (hole punch)? And would Jano be guilty of the 10th commandment (covetousness) or the 8th (theft)?

It's a good thing that 70+ years separate me from those bikes because my inner 9-year-old only wants to take one for a ride, just a short ride, back to my house and then stash it behind the bushes.

I love the old-fashioned kickstands on the bikes. Lifts the whole rear wheel off the ground. Better than the ones on newer bikes.

This picture seems to pack a hole lot of punch.

Is it not possible that there’s a big tree right behind us, with overarching boughs reaching forward but just out of sight, creating the dappled light at our feet from the low setting sun?

[The sun is almost directly overhead - see the shadow of the bicycle. - tterrace]

Is that La Luna in the background? The shadows and the lack of flair flare in the lens indicate it is not the sun. Maybe it's a home run.

[Hint: The answer can be found in any stationery or office supply store. - Dave]

Gibbous moon, caught with a long lens, maybe?

You're right. Must be a UFO.

Space ships seem to like to visit DC (ala The Day the Earth Stood Still)

1942's sign: "Short Cuts Prohibited" Today's sign: "Keep off the field or risk prosecution"