It's not just the Sun that can produce rainbows; the Moon can too.

A photo recently taken by someone driving home at night who happened to see this rare sight was published the other day in the national press, and can be viewed here:-

http://www.dailymail.co.uk/sciencetech/article-1224937/Rainbow-dark-Bright-Moon-creates-stunning-arc-night.html

Stunning photos of other moonbows can be seen here:-

http://www.starrynightphotos.com/planet_earth/lunar_rainbow.htm

And here:-

http://www.atoptics.co.uk/rainbows/bowim51.htm