The Moon

That would be a 22° halo, a fairly uncommon atmospheric phenomenon where light refracts through hexagonal ice crystals in the atmosphere resulting in an average deviation from the angle it comes in at by around (funnily enough) 22°.

There are lots of other interesting atmospheric phenomena including sundogs, moonbows, and the much rarer 46° halo!

the much rarer 46° halo

If that's the really huge halo that seems to take up most of the sky, I've only seen that perhaps 3x in my life.

Are they not collectively called coronas, in your part of the world? They are here.
- Yeah that's the one! Only seen it once (coinciding with a supermoon which was frankly surreal).
  
  Coronas are a bit different I believe, though another one of the same group. I've always just called them their individual names, with coronas being tighter and more spectrally-distorting than halos. Maybe the only other collective name I've heard would be the minimally descriptive "atmospheric phenomenon" but that's no fun at all.
  
  Edit: Just took a brief look and indeed coronas are related but formed by refraction through water droplets rather than ice crystals! Cool to know!

We saw the same tonight as well from northern Italy about 2 hours ago. The moonlight interacts with ice crystals in the air and creates this rainbow / halo 🤯

Yeah, if there’s an atoptics (I think that’s the word) community, they’d be all over that!

Ice crystals. The old-fashioned name for it is a corona, and according to folk wisdom, a corona of that size is usually a harbinger of cold weather coming.

This is the 22° halo. A Corona is an entirely different phenomenon caused by diffraction and interference of light around tiny water or ice particles, or other such particles of similar size. Halos on the other hand are formed by refraction. Here's another great resource about coronae (and pretty much every other atmospheric optical phenomenon out there).

You're correct about halo phenomena being caused by ice crystals. As such, they are most often observed when there's Cirrostratus in the sky, and that in turn is often the result of an incoming warm front. The Cirrostratus may start to thicken into Altostratus and Nimbostratus, so overcast and rainy would be the safest bet.
Thanks for sharing this. Here's one that I saw a while back

Jupiter just hangin on the right

I could see it this week even in the middle of London
- Yeah same can see it from Hornsey

I just took a picture of the moon, came out pretty good.

Don't read any of the other explanations, they just spout off the same thing they want you to think!

I did my own research, it turns out this is due to ice crystals. The inside of the dome set on top of the flat earth is covered by LCD displays. These displays get cold in wintertime and ice crystals form within the displays. This causes all sorts of visual glitches, like these halos around the moon. When it warms back up the ice crystals go away and the moon looks normal again.

Don't let people fool you with bullshit stories about ice crystals in the so called atmosphere. It's a totally made up story, with just enough truth in it to make it believable.

Cute.

No idea what is creating the halo

If not the cloud cover or other atmospheric conditions, the lens of the camera the image was taken with. Was the halo visible to the naked eye or only in the photo?