Sun halo over Mexico City, May 2015.

Sun halo over Mexico City, May 2015. Image by Jose Miguel S / CC BY-SA 2.0

It’s a natural phenomenon, a halo around the sun caused by light passing through ice crystals, but some Mexico City residents saw it as something for more forbidding when one was visible in the city on Thursday. Dozens phoned the National Weather Service to ask if it was a bad omen and if it meant it was going to rain more. Others joked that it was the start of a UFO invasion. Jose Manuel Caballero, at the National Weather Service, pointed out ‘It’s very common. The thing is that people never look up.’. Read more: