UMBRELLAS OVER THE EARTH

Press, Volume CII, Issue 30284, 9 November 1963, Page 8

UMBRELLAS OVER THE EARTH

Rainfall Affected By Moon’s Position [Specially written for “The Press" by JIM HALL] C’.5.1.R.0. scientists in Sydney believe the moon and the planets, Mercury and Venus, periodically act as “umbrellas” over the earth. They are confident that, in certain positions, the moon tends to lessen rainfall and that the two planets shield the earth from magnetic storms. Their conclusions, based on high-altitude research with American U-2 aircraft and balloons and plain pencil-and-paper calculations, have caused considerable excitement among scientists and astronomers in Australia and abroad.

A Radiophysicist Mr Kieth Bigg, aged 36. established the: nature of the planets’ influence on the earth while following up work on moonrain associations by Dr. E. G. Bowen, chief of the C.SLR.O. Radiophysics Division. At the same time he unravelled the mystery of the: occasional disappearance ofj the “blue haze” around the l red planet Mars, which has: been puzzling scientists for 50 years. His discoveries hinge on the basis that earth is “blanketed” by all three major bodies between it and the sun—the moon, Venus and Mercury. - Their positions have a direct bearing on the duration and size of geomagnetic disturbances in the atmosphere. These show themselves in various forms, including:— (1) International radio blackouts, caused when the usually calm ionosphere, 60 miles above earth, goes crazy. (2) Auroras, the strange display of coloured light at the Arctic and Antarctic Poles which upsets: radio frequencies used by: nearby defence installations. (3) Intense magnetic storms, which can confuse shipping and aircraft navigation. The disturbances are set off by charged atomic particles travelling towards earth in the solar corpuscular

stream, which is spewed out! in all directions by flares, i sunspots and other volcanic activity on the sun. All these effects have been! recorded for 100 years or so. | Studying such existing data and plotting lunar positions against magnetic activity in the atmosphere, Mr Bigg found there is a pronounced reduction in magnetic storms, radio black-outs and other disturbances when the moon moves between the sun and earth. One mechanism which might account for this is an electrostatic charge of about 10 million volts on the moon which repels or deflects the sun’s particles off course. Dust Particles Mr Bigg's findings are also reconciled with the scientists, view that the moon influences rainfall. Dr. Bowen, who has done world-acclaimed work in this field, believes dust particles from outer space form ice-crystals which form, melt and reach earth as raindrops. The particles, which have been collected on special filters by U-2 pilots, are thought to be bits from meteor showers. Dr Bowen believes that when the moon shields the earth from such showers, rainfall is less likely. His theory is supported by radar measurements which indicate that meteor rates vary in a similar way with the moon’s phases.

Additionally. there are Australian, New Zealand and United States figures showing that chances of heavy rain during the week after a new moon and full moon are up to three times greater than for the week preceding the new moon. “The man on the land has always instinctively known that the moon affects rainfall,” says Dr Bowen. “Meteorologists have scoffed at the idea, but now science has proved the farmer to be right.” Intrigued by his moon findings, Mr Bigg turned his attention to Venus and Mercury which exert no influence on rainfail. And his arithemetic again showed a shut-out of most magnetic storm-interference when either planet crossed the sun’s line with earth. Venus, our nearest space neighbour, 26 million miles away, crosses the line every

583 days: Mercury every 116 days. Each crossing means about two days of comparative calm in the magnetic field above earth. As with the moon, one explanation is that each planet carries an electrostatic charge which deflects the particles in th esun’s stream Thus they act, briefly, as umbrellas over the earth. These results led Mr Bigg on to his discovery about the earth’s effect on the blue haze surrounding Mars. The haze obscures the planet’s rocky surface for most of the year, but. on occasions, it suddenly clears completely for a few days. Many theories have been suggested for the phenomenon. Now Mr Bigg seems to have established the correct one. According to his calculations, the haze disappears about the time earth passes in front of Mars, or Mars ducks behind earth.

Small Cost The earth, he believes, temporarily blocks out the sun’s solar stream which causes the haze. “Very simple, but no one ever looked at it this way before,” says Dr. Bowen. “It is the same story with the other findings. “All this is brand new stuff, and yet it is all in the data. “It is a beautiful illustrtion of how, in this age of expensive intricate research with space vehicles, you can still get exciting knowledge' just by looking at the records. “Mr Bigg’s work on the planets has been done in the past few months with not much more than a pencil and paper and at very small cost “And this is not the finish by any means. We are now investigating the other planets for similar effects. “The next thing we shall do is look at Jupiter, which is encircled by its own 12 moons. They seem to have the same effect on it as our moon on earth. Then we will ■extend our research to Saturn and the rest of the solar system.” And the practical results of all this scientific discovery? It may eventually mean changes and advances in weather forecasting and communications systems. “Meanwhile,” says Dr Bowen, “it has given us all kinds of ideas for measurements with space probes. We particularly want to know the electric charge on the planets—they could be smaller than the moon’s.”

“Sonny Boy Williamson represents the ’country blues' side of the festival He must not be confused with the performer of the same name ... who was stabbed to death in 9148.”—From a handout by the British National Jazz Festival.