NO LIFE ON VENUS

Manawatu Herald, Volume XLIV, Issue 2439, 10 June 1922, Page 4

NO LIFE ON VENUS

LIKE THAT ON EARTH.

SO SAYS A PRINCETON PRO-

FESSOR

Dr. Henry Noi’ris Russell, Director of the Princeton Observatory. said recently that the searches into the atmosphere of Venus, in which he had participated, failed to show whether or not the planet might he the home of life. Dr. Charles E. St. John, of the Mount, Wilson Observatory, who played the leading part in the investigation of "Venus which was described in the New York Times to the American Astronomical Society, found traces of oxygen and water vapour on Venus. The oxygen was sufficient to sustain life in the belief of some astronomers. Dr. Russell argued that oxygen had not been proved to he necessary to, sustain life, and that it misfit exist in atmosphere only as a by-product of life. Although it is the nearest planet to the earth, nearer, at times than Mars, Venus has thoroughly baffled investigation heretofore, because it has an unmarked-{sur-face and because it is in darkness, being between the earth and the sun when it is nearest the earth. Such markings as those which characterise Mars are lacking. This is supposed to be due to as envelope of cloud covering evenh the surface of Venus. PRAISES OF DR. ST. JOHN. Dr. Russell said that the detection of oxygen and water vapour had been accomplished by Dr. St. John in remarkably fine work on the spectroscope, an, instrument of which he is one of the greatest masters.

The presence of oxygen in the atmosphere of Venus was detected because the atmosphere of Venus darkened the light produced by the oxygen in the sun. The spectroscope analyses the sunliglit_into narrow lines of different colours, produced by the atoms of the various elements of the sun. But after being reflected by Venus darkened lines, or what are called “absorption lines,” showed that the oxygen and water vapour of Venus had absorbed some of the light. This clearly showed the presence of those two substances in the atmosphere of Venus.

The difficult part of the experiment, however, was the fact that the.oxygen and water vapour in the atmosphere of the earth acts in exactly the same way on the sunlight. The reflected light of Venus had to pass through the atmosphere of the earth. The problem was to get rid of the interference of the earth’s atmosphere. This the astronomer succeeded in doing. AS SEEN ON THE SPECTRUM. When in rapid motion towards the earth, the light from Venus, or any other body, shifts slightly towards the violet end of the spectrum, and when in rapid motion away from the earth, shifts towards the red end. It requires measurements dealing with billionths of an inch to measure the shift, but it can be done. Dr. St. John succeeded in this way in separating the oxygen absorption line of Venus from that of the earth, so that they appeared side by side, like a misprint, instead of fused together. Having isolated these lines of Venus, he was able to measure them.

“He concludes,” said Di\ Russell, “that the amount of oxygen above the visible surface of Venus is much less than 1 per cent, of that above the surface of the earth, the amount of water vapour also small in proportion. “If the visible surface of Venus is composed of clouds, most of the planet’s ‘ atmosphere may lie below this. This may explain the difficulty about water vapour, because there is very little water vapour above the earth’s atmosphere above the level of the highest clouds.

“But there is a good deal of oxygen in the earth’s atmosphere above this level, and in this ease further explanation is necessary. Among the possible explanations there is much in favour of the belief that the oxygen in the earth’s atmosphere has been produced by the action of green plants. This and other considerations make it probable tha the earth had no free oxygen in its atmosphere, although there may have been a large quantity of carbon dioxide or other oxygen compounds. A planet on which life did not exist, on this theory, would have no free oxygen in its atmosphere.

LIFE THEBE IMPROBABLE. “The question whether ' life would necessarily develop upon a planeti' possessing sufficient water in its surface cannot, so far as I know, be definitely answered in the present state of science. It seems probable that a very delicate balance of conditions may have been necessary in order that life might originate, and that, therefore, some condition on Venus, the higher temperature, may have prevented life from getting started there. In any case Dr. St. John’s observations make it practically certain that there is no life on Venus of a character similar to that which exists on the earth.” In the belief of “many astronomers, Venus always presents the same face to the sun as the moon does to the earth, but Dr. Russell said that Dr. St. John’s study of the T#anet indicated that it probably rotated slowly, certainly not more rapidly than once in fifteen days. • He said that the blanket of cloud would probably save

the part facing the sun from extreme heat, and keep the other hemisphere warm during its unlighted period, so iliat the long days and nights on Venus would not necessarily interfere with the developmet of life.