Have you ever seen a rainbow after dark? It happened last night in Yorkshire, UK, where Christopher Walker photographed a multi-colored band arcing over the countryside:
Rainbows appear when sunlight is reflected from raindrops. But in this case, the sun was not required; the Frosty Moon was bright enough to do the job on its own. "The moonlight was so bright I could see red in the rainbow with my unaided eye," says Walker. "A 30 second exposure with my digital camera revealed [the full range of rainbow colors]."