EARTH IS MOVING AWAY FROM SUN

Southland Times, Issue 23773, 22 March 1939, Page 9

EARTH IS MOVING AWAY FROM SUN

UNABLE TO SUPPORT LIFE IN TIME , SMALL DISTANCE EACH CENTURY “The ■ earth is actually moving away from the sun, but only a very small distance each century. That is not very fast, but in millions of years to come there will be a difference in temperature on the earth. There will be a time when the earth will be unable to support life. Do not be alarmed. It will probably take about 2,000,000,000 years.” These statements were made by Mr M. Geddes, of South Hillend, who was recently appointed director of the Carter Observatory, Wellington, in answer to a question at the end of a talk given by him at Winton on “The Wonders of the Skies” to assist the funds of the new Presbyterian Church. At the beginning of his address, _Mr Geddes said that in the earliest time people must have wondered about stars and what appeared in the sky. Those early vague wonderings were probably the beginning of astronomy. The science today was in a very advanced state and it was useless looking at a book on astronomy more than six months old. He did not want all statements taken as hard and fast truths because in six months’ time or later they might be wrong. He would give only the latest opinions on them. Mr Geddes said that from the earliest time very many things in the sky were a puzzle. The fact that the sun rose in the east and sunk in the west was a puzzle. Later on it was found that the things in the sky did not move but it was the earth itself that rotated. Later planets were discovered. There were nine known planets. The planet Venus could be seen last year. At the present time the planet Mars could be seen to the south of east each night at 10 o’clock. On July 23 Mars would be closer than it had been for the past 12 years and still closer early in 1941. It was a reddish planet. So far Mars was the most interesting of the planets and it appeared that it would sustain life. For about 20 years many people thought there were canals on Mars, but later someone pointed out that it would be impossible to see a canal from 30,000,000 miles away. It was also pointed out that for canals to appear as lines they would have to be 100 miles wide. In 1900 it was finally decided that canals did not exist and that the lines were marshes. There was no evidence of intelligent life there, but there was evidence of a low vegetation. A polar cap could be seen on the planet and when the cap decreased the surface became a light green and when it increased it became a dull brown. It had an atmosphere, but it was probably like that at the top of Mount Everest. The earth had one moon. Mars had two, one red and one green, but they are very tiny One moved round in 12 hours and the other in 24 hours. They rose at different intervals and passed each other in the sky. Beyond Mars there were small planets and beyond that again _ Jupiter which would be seen later in’ the year before daylight. Jupiter was considerably larger than the earth and had no fewer than 11 moons. / TWO MOONS DISCOVERED Mr Geddes remarked that if asked a few months ago how many moons Jupiter had he would have said nine, but since then two more had been discovered. Not much was known of this planet except that the surface was frozen hard and was obscured by frozen clouds. Further out was the planet of Saturn, which was smaller than Jupiter. Nine moons had been discovered there and the most interesting thing about it was that it had a ring like a halo. It was very plain and could easily be seen, perhaps with binoculars. The ring was a puzzle for some time, but it was now thought that a tenth moon had broken up into millions . of pieces and they rotated round the planet. The surface was frozen. There were three planets behind Saturn. The first was Eurinus, with four moons. It could just be seen without a telescope. The next was Neptune, discovered about 1846. There was i.ot much known about it. It was 2,000,000,000 miles away and had two moons bigger than the earth. The ninth planet was Pluto, discovered in 1930, and there was practically nothing known about it. There was probably a tenth behind it. The whole system of the planets rested on the central body, the sun, and they were held in their paths by the pull of the sun. If the bodies were not moving, the sun would pull them into its surface. Mercury was the nearest planet to the sun and little was known of it, as it was hard to see. One thing that was known was that it turned only one side to the sun. One side of it was molten and the other side frozen. Mr Geddes said that the moon had no atmosphere and appeared to be a dead world. It was very mountainous and many of the mountains were named. Its diameter was about a quarter or a third of the diameter of the earth. “VAST BALL OF GAS” The sun was a vast ball of gas and sunspots were a kind of eruption or storm on the surface. Seen through a telescope at the present time, there were about 30 or 40 spots on the sun. Some of these eruptions of gas shoot up at the rate of about 1600 miles a second and reached the earth. Then there was an aurora or a fade on the wireless. From 1933 to 1937 spots had increased on the. sun and some had been large enough to see with the naked eye. These were at least 30,000 miles across. It could not be said that sunspots caused fine or wet weather, but it was said that they made abnormal weather, not necessarily bad weather.

It was thought that sunspots affected vegetation. In the rings of a felled tree, it had been shown that there had been more growth during the years when sunspots had been most abundant. The two stars at the foot of the Southern Cross were called the pointers, said Mr Geddes. The brightest one was the closest and was actually 25,000,000,000,000 miles away. The light from this star had been travelling four years and one-third to reach the earth. When it was looked at now, it was seen as it was in 1935.

Mr Geddes explained that all stars were not the same. In the Southern Cross, one was red and another pure white. Some stars were yellow and some orange. The age of the stars was indicated by their colour. The sun was yellow, which showed that it was past middle age. Mr Geddes also spoke about the Milky Way and mentioned that nobody had so far attempted to say how many stars there were in all the universes. He said that quite possibly there were other worlds with human beings on them, but probably that it would never be found out. There was an attendance of about 50 persons. The speaker was introduced by Mr W J Bennett, who said that Mr Geddes had taken an interest in the affairs of the district during his stay, especially school enterprises. A vote of thanks to the speaker, moved by the Rev. John Newlands, was carried by acclamation.