I have heard about this before but this question is directly prompted by the YouTube video below. The film is the one at the top right. It shows all kinds of weird moving things filmed from spacecraft. What are those?
UFOs?
Well you can bet they aren’t some alien life form jetting around. Known and unknown natural phenomena are (is?) so diverse, the eleventy-billion-to-one answer to your query is “we don’t know yet,” not ET.
They’re droplets of water on the window.
Actually, for a number of the clips, it did appear to me that they were not shots of space, but films of microscopic activity in some sort of fluid. In several clips, there seemed to be a sort of Brownian motion among a lot of the objects.
Has anyone, here, seen any zoom photography taken in space? Is it natural for objects several millions of miles away to go out of focus simply because the lens is being zoomed in or out to/from an object only a few hundred kilometers away?
IANAM, but elves, sprites and jets (in the weather phenomena sense) were only discovered relatively recently. It wouldn’t surprise me if some of the objects filmed were also connected to thunderstorms, somehow. Certainly in some of the scenes there is some thunderstorm activity in the clouds below.
I gave up partway through that video, but I saw perhaps one cosmic ray, two Irridium satellites, and a few thousand out-of-focus specks of dust, which would have been perhaps a few inches in front of the camera. Now, maybe aliens are a lot smaller than we thought, and their spaceships are dust-sized, but I’d hardly call that conclusive.
No. Everything further from the lens than the (focal length)[sup]2[/sup]/F[sub]stop[/sub] focuses as a group (Hyperfocal Distance ).
For a 100mm diameter 1000 mm focus lens (F10) stopped to f22 that’s anything over 45.5 meters. You’d need an outrageously long focal length lens to resolve focusing differences between objects 1 vs 2 km away.
That makes such depth of field issues as you noticed an excellent way to spot fakes.
“For thousands more years the mighty ships tore across the empty wastes of space and finally dived screaming on to the first planet they came across — which happened to be the Earth — where due to a terrible miscalculation of scale the entire battle fleet was accidentally swallowed by a small dog.”
[right] – The Hitchhiker’s Guide To The Galaxy[/right]
Stranger
Those who study the complex interplay of cause and effect in the history of the Universe say that this sort of thing is going on all the time, but that we are powerless to prevent it. “It’s just life,” they say.