Atmospheric Phenomena By Professor Carolin Crawford

Astronomers are often also keen observers of atmospheric phenomena – probably stemming from an ingrained habit of keeping a weather eye on the sky in case it’s going to be clear that evening!

Such phenomena are illustrations of physics – and particularly optics – in action. The incoming sunlight, moonlight and starlight fall on the Earth, and the myriad of different ways it interacts with the air molecules, particles, water droplets, ice crystals and dust in our atmosphere cause it to be reflected, refracted, diffracted, dispersed, absorbed and scattered to produce a whole host of spectacular mirages and effects. Many of these apparitions are relatively predictable, some occur commonly; while others are so rare that you are very fortunate if you ever witness them.

You may have already noticed some of the atmospheric phenomena I shall be talking about, but didn’t really think about what you were observing; others you…