Rainbow, Moonbow & Fogbow Gallery

To see a rainbow you need sunshine and falling rain. Rainbows are more rare than might be thought. Early morning and late afternoon are the best times to see them because the Sun must not be too high. Rainbows are always opposite the Sun so their centres are below the horizon at the the anti-solar point. The lower the Sun the higher the bow. Red is always outermost in the primary bow with orange, yellow, green and blue within. Occasionally, when the raindrops are small, fainter supernumerary arcs of vivid green, pink, and purple lie just inside the main bow. A rainbow is not just a set of coloured rings. The sky inside is bright because raindrops direct light there too. The primary bow is a shining disk brightening very strongly towards its rim. Description by Les Cowley.