A ‘smile in the sky’ captured the imagination of a Wisbech Standard reader when it appeared over head in Tydd St Giles.

Cambs Times: Near Wisbech on Saturday when my son saw a circumzenithal arc - inshort a rainbow appearing in the sky, formed through ice crystals in theatmosphere.Near Wisbech on Saturday when my son saw a circumzenithal arc - inshort a rainbow appearing in the sky, formed through ice crystals in theatmosphere. (Image: Archant)

Marvin Maitland captured the moment the optical phenomenon appeared on Saturday January 16 on his mobile phone after his seven-year-old son Eden pointed it.

Marvin explained: “I was watching Eden roll down a gentle slope as he was playing with a friend when he suddenly looked up at me and asked ‘what’s with the rainbow in the sky?’

“I asked what rainbow because I couldn’t see anything, but he kept pointing and I eventually spotted it. I’ve never seen anything like it before so I thought I’d better capture it on camera so I could show other people,” he explained.

The Marvin and his family were visiting friends in the village when Eden made his unusual spot, which looks like an upside down rainbow and is called in fact called a circumzenithal arc or Bravais’ arc.

It is an optical phenomenon and although it looks like a rainbow it actually belongs to the family of halos arising from refraction of sunlight through ice crystals.

Although many people may not have seen one, they are in fact more common than rainbows. But because they form a considerable distance (approximately 46 degrees) above the sun they are not always spotted.

And because they look like an upside down rainbow they are dubbed ‘a smile in the sky’.

Its colours, ranging from violet on top to red at the bottom, are purer than those of a rainbow because there is much less overlap in their formation.