It can get foggy on winter mornings near Canberra … The image above was snapped just after sunrise in late July, when the temperature was a bracing -2 degrees! DSS 43, the 70m antenna, stands about 73-metres above the valley floor and was catching the first rays of sunlight. Conditions were also just right for a fog bow to have formed. Fog bows are sometimes called white rainbows, as they are similar phenomena. Rainbows are caused by rain drops acting like prisms, but due to the much smaller size of water droplets that form fog, a fog bow has only very weak colours, if any are visible at all. Diffraction broadens the light reflected by the water droplets, smearing out the colours to give the characteristic white ring. (Image credit: @CanberraDSN)