OCR Text |
Show Rings About Sun and Moon The weather bureau says that there are two kinds of rings about the sun and moon. Those that are close m only one to four or five diameters of the moon, say, away which we call coronas, are caused by water droplets. The smaller the droplets the larger the rings. The other rings, the true halos, occurring occur-ring much farther away, are caused by Ice crystals. There are several such rings, but each one always has the same angular size. The size depends on the . shape of the crystals . (usually., but not always, a short six-sided column with flat ends perpendicular to the sides), the course of the light through the crystals and the amount of banding band-ing this, light undergoes as It enters a face of the crystal at a given slope. |