EARTH'S OXYGEN

New Zealand Herald, Volume LXXVI, Issue 23273, 16 February 1939, Page 6

EARTH'S OXYGEN

EXHAUSTION POSSIBLE FORECAST BY ASTRONOMER ' CONDITIONS ON PLANETS [i'tOM A SPECIAL CORRESPONDENT] LONDON. Jan. 26 The time may come when the oxygen in the atmosphere will be exhausted. The earth will then resemble Mars. This forecast ot the ultimate fate of the earth was made this week by the Astronomer lloval, Dr. H. Spencer Jones, when lie delivered in London the Norman Lockyer Lecture of the British Association for the Advancement'of Science.

Investigations of recent years, said the lecturer, had led to tho following conclusions concerning the planets:— Mercury. —The evidence of an atmosphere on Mercury is not fully conclusive, but faint and transient shadings on tho planet have been interpreted as indications of an atmosphere. It is certain, however, that most of tho original atmosphere must have boon lost.

Tho Earth.—Whenever organic matter is buried, as in coal measures and oil deposits, so that it cannot become oxidised and decay, there is a net gain of oxygen to the atmosphere. It seems probable that the present abundance of oxygen in the atmosphere has been provided in this way, and that, if the coal, oil and other organic deposits could bo imburied and completely burned, the whole of tho oxygen in the atmosphere would bo used up High Temperature on Venus Venus. —It may bo expected that Venus will have an atmosphere comparable with that of tho earth in extent and density. Tho presenco of an extensive atmosphere is confirmed by observation. It is not improbable that tho temperature on the surface of Venus 'may be as high as, or higher than, that of boiling water. The high temperature, the lack of oxygen and tho abundance of carbon dioxide, can be interpreted as indications that there cannot be any great amount of vegetation on Venus, and suggest that the planet is not the abode of life.

Mars. —The red colour of Mars, which is unique among the heavenly bodies, provides indirect evidence of oxygen, suggesting rocks that have been completely oxidised. We may contrast tho colour of Mars with the grey, or brownish, rocks of the Moon, which have not been oxidised. Earth May Reach State of Mars It appears probable that Mars may be a planet where tho weathering of the rocks, followed by their oxidation, has resulted in the almost complete depletion of oxygen from the atmosphere. Mars appears to be a world in the state that the earth will ultimately reach when the oxygen in the atmosphere will have boon almost exhausted by the progressive weathering and oxidation of the rocks. Jupiter and Saturn. —The telescopic appearance confirms the existence of dense atmospheres. Jt used to be thought that the rapid changes shown by the markings on Jupiter were indications that the planet was hot. It is now shown that Jupiter must be intensely cold.