What you are looking at is a phenomenon known as Ball Lightning. It forms triangles which move as a single object, which is an identifying feature. Such a triangle is at the lower left. It vanishes and appears at random, and is often associated with earthquake/volcanic tectonic stresses.
Yeah I know, it's a reflection off a weather balloon under the light of venus and somebody flushed an alligator and that's what you get.
It's well known that flares form perfect triangles right? Yeah-huh. Weird how this particular phenomenon is always poo-poo'd and treated as tinfoil… I bet it has 'applications' other than simple light, eh?
https://en.wikipedia.org/wiki/Ball_lightning