Or pictures of astronomical or meteorological phenomenon that do the same?
I’ve heard so many dismissals of ‘sightings’ that have used these explanations, that I would like to see for myself what people are getting in such a flap about.
Yup, that’s one of the phenomena I expected. I think you’d have to be pretty dumb, or have a very vivid imagination to think one of those was an intelligently operated flying vehicle of some sort, though.
Lenticular clouds, in the right lighting, and to someone not used to them, would look like “something I’ve never seen before” - the usual claim. I wrote about quite a lot of different atmospheric effects which have been identified as UFOs in my book, “The Skeptic’s Guide to the Paranormal”. The most common I have been involved with were when there was a temperature inversion layer. Bright lights from the ground, or the reflection of the sun from a lake - in the right conditions and at the right angle - can produce a bright light in a clear sky (a total internal reflection off the inversion layer) which will not show up on radar. It appears to move with the viewer, especially if they are in a car. It will suddenly appear or disappear, when the angle of incidence gets within the critical angle, and the instability of the inversion layer itself can cause colour effects around the edges of the image.
Compare these newspaper headings:
Many people see UFO!
Many people saw total internal reflection from an inversion layer.
In one case I worked on, the reflection was from laser lights being used in some advertising promotion nearly 100 miles from the sightings. The angles involved led to that. Hard to explain without a ray trace diagram. The first headline was front page news, the second article (headed something like “Bureau of Meteorology gives explanation for UFO sighting”) was in the bottom corner of page 7 a week later.
The newfoundland UFO was identified as jet contrails (or cloud). There are apparently a few hundred of these observations. To the point they have a name: December sightings.
I dunno, that first image result looks like something straight out of Billy Meier’s bag of tricks.
Venus is often mistaken for a UFO, and IIRC the reports of sightings increase quite a bit when the brightest planet is visible. There’s a pic here.
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Sundogs can look pretty mysterious at times, especially when coupled with contrails.
Sun pillars, and ice crystal halos also bemuse people, as can nacreous clouds.
Take a look at Atmospheric Optics for more examples and photos.
Picture of a sundog. I’ve seen & photographed them myself and they’re really nifty.
Many people ask me if atmospheric phenomena could be responsible for sightings of UFOs, and I wonder if people could really be that foolish.
The assorted suggested phenomena doesn’t look anything like intelligently piloted craft. It sounds like an explanation cooked up to brush off something the author of the idea won’t even consider possibly being real.
I think mental disturbance, or some unknown cause are more likely than lenticular clouds being the culprit.
Maybe some people want to make those who see UFOs look crazy.
I wonder.
It sounds like you’re suggesting:
• Sightings are more likely a result of the observer’s mind not working correctly.
• Certain people want these observers to seem like their minds aren’t working correctly.
I’m confused. 
I’ve seen a UFO, and not one that could be explained by (known) atmospheric phenomena.
But it still makes sense to consider such explanations first, firstly because people do mistakenly identify, say, Venus as being a nearby craft.
And secondly, even if such mistakes were rare, we should still consider these explanations because they are simple and readily checked (e.g. we know where Venus appears in the sky on any given date, and the meteorological office can probably tell us if there were any unusual cloud formations).
Ball Lightning
If you look at early UFO photographs, few of them resemble atmospheric effects: film scratches, tossed hats, and reflections of streetlights, yes, but not all that many sundogs or Kelvin Helmholtz wave clouds.
Many people think it is either one or the other. That is what I am suggesting. I wonder which one?
So eliminating the utter idiots is a good use of metrogly, but I am only saying it alone(certainly good be a contributing factor for crazy idiots) makes up a small number of the cases.
I think it is mostly crazy people, or a conspiracy.
If you’ll take an anecdote…
It was a dark and rainy night (no really, it was). I was driving on a rural two lane highway, encountering patches of fog, mist, etc. Virtually no traffic. Cloud cover was relatively low. Off to my right, I saw the strangest light I’ve ever seen. I was convinced it was…something…maybe a UFO, so I pulled over, careful to keep the driver’s side wheels on the pavement so as not to get stuck, and got out of the car for a better look. As soon as I did that, I heard the engines, and realized where I was…about 20 miles north of the biggest airport in the area, and right about where the run-in line would be for a plane on an instrument approach. The odd light was the landing lights on the airplane, diffused through the clouds and mist.
Well see out of the many diagnoses that could be called “crazy”, most of them do not involve the kinds of hallucinations or delusions you’re referring to. It’s one of the myths that those of us with such conditions are up against. (Also, it’s not the same as being an “idiot” since our intelligence is not lower than anyone else’s.)
As for conspiracies, there are plenty of reasons why those “theories” don’t fly but that’s a whole 'nother thread.
How about a superior mirage?
I did see a strange object in the sky several months ago. This isn’t exactly what the OP asked for because I don’t think it was an atmospheric phenomenon, strictly speaking. It was an upside-down teardrop-shaped object, lavender in color, in the Western sky. A lot of people saw it and apparently it was explained as a weather balloon. That made sense to me, but not to the UFO enthusiasts I am acquainted with. They said the weather balloon explanation was complete malarkey because people on the California coast also saw it in the Western sky (and we are in Phoenix). Not being a mathematician (or whatever appropriate specialty) I don’t know whether our elevation would enable such a sighting from both places. But it didn’t change my opinion about little green people.
I have seen Venus, a lenticular cloud, and even a streetlight- all of which caused me to go “WTF is that a UFO?!?” For a minute or so.
Yep, and the difference between you and other UFO spotters is that the others don’t look critically at what they’re seeing, so they never get to the “aha!” stage and realise what they’re really looking at.
I’ve been completely bamboozled by the Moon as a child, it was bright red, low to the horizon and appeared to be chasing our car. It took a long while before I figured out what I was looking at. I’ve also seen a bright steady light inside a towering cumulus cloud that I can only assume was some kind of strange reflection or ball lightning (but the cloud hadn’t reached the mature stage yet, so normally you wouldn’t expect lightning.)