photo #8481461

At sunrise and sunset, the Sun’s rays have a long way to travel through the Earth’s lower atmosphere. Dust and other airborne molecules scatter the rays of light, with the short-wavelength blue and green colours getting scattered the most, and the long-wavelength red and yellow colours getting scattered the least. This is why we get rosy, golden, and scarlet skies at the start and the end of the day. And it is why, when there are raindrops in the air to reflect and refract the encrimsoned sunlight, we get red rainbows – like this one spotted by Joe Rogan (Cloud Appreciation Society Member 63,735) over Alexandria Bay, New York, US, with an accompanying Cumulonimbus featuring a blushing pink arcus.