Daily Archives: May 7, 2018

Last week there was a ring around the sun for much of the day. This ring is called a halo and is caused by ice crystals interacting with sunlight.

A halo is a whitish ring that encircles but does not touch the sun. It can also have some color; the most discernible is a faint red tint around the inside of the halo. It is an optical phenomenon that owes its existence to the bending of light by ice crystals, much like the “rainbow crystals” you may hang in your sunlit windows. Continue reading →