Sun Halo in Namibia These sun halo pictures were taken near Otjiwarongo, Namibia in November of 2011... Enjoy! A halo is an optical phenomenon produced by ice crystals creating colored or white arcs and spots in the sky. Many are near the sun or moon but others are elsewhere and even in the opposite part of the sky. They can also form around artificial lights in very cold weather when ice crystals called diamond dust are floating in the nearby air.