Models pose for a photograph backstage before the Miss Koch beauty pageant, titled “Getting to Zero Teenage Pregnancy”, at the Korogocho slums in Nairobi, December 6, 2014. The winner of the pageant, Miss Koch Kenya, will represent and lead the non-governmental organization to encourage youths in slums to overcome challenges such as poverty, crime, drug and sexual abuse, according to organisers. (Photo by Thomas Mukoya/Reuters)

A customer buys a box of bullits and a target of Osama Bin Laden October 3, 2001 at Blue Ridge Arsenal in Chantilly, VA. Guns sales have risen across America since the September 11th terrorist attacks. (Photo by Mark Wilson/Getty Images)

Brazilian gymnast Jade Barbosa is seen during a training session at the new Brazilian Artistic Gymnastics Center in Rio de Janeiro January 16, 2015. The Artistic Gymnastics Center is where gymnasts are preparing for the 2016 Olympics. (Photo by Sergio Moraes/Reuters)

“Hard for Life”. (Photo by Theo Vu Xuan/Sony World Photography Awards/WENN.com)

Aleksandra Krunic, of Serbia, drops to the court after defeating Petra Kvitova, of the Czech Republic, during the third round of the 2014 U.S. Open tennis tournament, Saturday, August 30, 2014, in New York. (Photo by Kathy Willens/AP Photo)

This breathtaking view from the world's tallest building shows a thick blanket of smoggy fog smother Dubai. The mist almost completely covers the huge sculptures which dominate the skyline. And the spectacular view from the Burj Khalifa – standing at a staggering 828 metres tall – shows the city engulfed by the thick fog. And the smoggy fog reaches heights of up to 400 metres as it rises above the impressive skyscrapers in Dubai. (Photo by Bjoern Lauen/Solent News/SIPA Press)

A fog bow is a similar phenomenon to a rainbow; however, as its name suggests, it appears as a bow in fog rather than rain. Because of the very small size of water droplets that cause fog—smaller than 0.05 millimeters (0.0020 in)—the fog bow has only very weak colors, with a red outer edge and bluish inner edge.