Rainbow that set the sky on fire

In a breathtaking blaze of glory, Nature puts on one of its most spectacular sky shows.

Reds, oranges, blues and greens create a flaming rainbow that stretches above the clouds.



But this circumhorizon arc, as it is known, owes more to ice than fire. It occurs when sunlight passes through ice crystals in high cirrus clouds. It is one of 15 types of ice halos formed only when the most specific of factors dovetail precisely together.

This blanket of fire, covering hundreds of square miles, is the rarest phenomenon of them all. It was spotted in the US on the Washington-Idaho border around midday last Saturday.