An upsidedown rainbow....

It was amazing to see this today. It's actually called a 'circumzenithal' arc and isn't a rainbow, but a halo. A quote from the met office page about them tells me that... 


‘They are formed when sunlight refracts through horizontal ice crystals at such an angle that the light enters the crystal through its flat top face and exits through a side prism face causing the distinctive upside-down rainbow effect.  They are commonly associated with cirrus clouds where ice crystals readily form.’


Amazing & quite a decent pic given that this photo was taken with a tiny £15 point and shoot camera :)