Mesmerizing Sun Halo

Last Tuesday, residents of New York and the surrounding area were privy to a really amazing celestial treat; it's called a Sun Halo, and one spent some time today hovering over The Big Apple and making people wonder if Martians were finally invading.

A halo is a type of optical phenomenon that can happen around the sun or moon. It's also referred to as a 22-degree halo because it forms a ring exactly 22-degrees from the sun. In order for a Sun halo to happen, a thin veil of high-level clouds has to put some hexagonal ice crystals at exactly right spot.