THE POLAR LIGHTS

Hawke's Bay Herald-Tribune, Issue 179, 16 August 1937, Page 11

THE POLAR LIGHTS

Caused By Sunspots . ELECTRICAL EFFECTS The Aurora Australis or Southern Light's, and the Aurora Borealis, or Northern Lights, take a great variety of forms, and the colours vary a great deal, being sometimes white and at other times yellow, red, green or blue. In a particularly brilliant display three colours are seen, "the lower part of the aurora being red "and the upper part green, with yellow in between. The aurora usually takes the form of great streamers, which extend across the sky, and from which rays of light' extend upwards. Sometimes these rays are stationary; at other times they llash and move, crossing each other like huge.searchlight beams, or shooting up into the sky and then receding again. Sometimes the aurora takes the appearance of glowing curtains hanging down from the sky, treinbling and folding just aa if they were being shaken by a wind. Men of science have been giviug a great deal of attention to these Polar lights in recent years, and it is believed that they are an electrieal or magnetic phenomenon. As the number of auroras follows very closely the appearance of sunspots, it is practically

certain that the aurora is caused by the sun. It is believed that streams of electrieal particles are shot out from the sunspots, which are enormous fiery storrns on the sun's surface. These particles travel acror- space at enormous speed, and because the earth is a magnot they; aro atracted to the 'North and South PolCs. Experiments which scientists have made seem to show that the auroral lights are rays given out when these eleetric particles from the sun strike clouds of frozen nitrogen crystals in the upper layers of the earth 's atmosphere. , The height of the aurora has been measured by making observations from two separate points. It has been found to vary a great deal, and seems to range from 50 to 600 cniles. A rather curious thing is that there is a close connection betweeh displays of the aurora and wireless fading and static. Whenever the aurora is seen it means that a magnetic storm, caused by the streams of electrieal energy shot out from the sun, is in progress. Not only wireless, in fact, is affected, but also the magnetic compass and the telegraph.