OTHER WORLDS WHERE LIFE EXISTS?

Wanganui Chronicle, Volume 83, Issue 68, 22 March 1939, Page 3

OTHER WORLDS WHERE LIFE EXISTS?

Astronomer Royal Makes Deductions. Venus and Mars

JJR. H. SPENCER JONES, the Astronomer Royal, in a contribution which appears in Discovery, the popular journal of knowledge, writes on the question, “Is There Life in Other Worlds?” He details the available information about Venus and Mars, and sums up by asserting:— “It seems that Mars is a planet where life may be on the verge of becoming extinct and that Venus is a planet on which life may be on the verge of coming into existence. Elsewhere there is no life of any sort” * j-JUT what is the likelihood that other stars have planets associated with them and that life may exist on some of these?” Dr. Spencer Jones goes on to ask. “To assess the probability that other stars have systems of planets we must be able to account for the origin of the solar system. “This is one of the most difficult problems in astronomy, which has not yet been completely solved in a satisfactory manner. The only hypothesis

which seems to account for the facts is to suppose that a few thousand million years ago another star passed close to the sun. The passage of the star raised a great tidal protuberance on the sun, which became greater and greater until a long jet of matter was drawn out. “As the stranger star passed on its way, the tidal wave on the sun subsided but the matter drawn out from the sun broke up and condensed into planets. The stars are so far apart that such a close encounter of two stars can rarely happen; calculation suggests that it may occur about once in five thousand million years. Hence planetary systems are not the rule, but very much the exception, and in our stellar universe there can be but few stars, in addition to the sun, which have systems of planets attached to them. “In any planetary system, everything seems to be weighted against the possibility of the existence of life: If the planet is too near its parent sun, it will be too hot for life to exist: if it is too far away, it will be too cold. “If it is much smaller than the earth, it cannot retain any atmosphere. IT it is

much larger, it will have retained too much atmosphere, for when hydrogen cannot escape the formation of the poisonous gases, ammonia and marsh gas, appear to be almost inevitable. “Amongst the vast number of stars in any one stellar universe, we should expect to find only a limited number with a family of planets; and amongst these families of planets there cannot be more than a small proportion where conditions exist that make life possible. “On the other hand we must remember the vastness of creation; there are about one hundred million separate universes in the region of space accessible to observation, and we know not how many more beyond. If in each universe there are not more than two or three dozen stars with families of planets, the total number of planetary systems within the relatively small region of space that we can survey is immensely great. “If the proportion of. planets on which life can exist is not more than one ' in a million —and our survey of the solar system suggests that this is a considerable underestimate —the total number of planets where conditions are suitable for life must be considerable. So it seems probable that there are other worlds where life exists, though that life may be entirely different from any form of life with which we are familiar.”