NEARBY WORLDS.

Auckland Star, Volume LIX, Issue 36, 13 February 1928, Page 6

NEARBY WORLDS.

After a period of voyaging off in apace to seek the most distant stars and the vastest nebulae, the minds of our astronomers seem to be coming back to our own solar system, to retill some of the fields of scicntific effort that are nearest home, Dr. D. H. Menzel, of the Lick Observatory, and Professor Henry Norris Russell, of Princeton, both have called attention recently to the probability that the outer planets of our system are cold worlds, with atmosphere of gases strange on earth because not even our coldest refrigerators are chilly enough to permit them to exist; worlds bathed, it is not impossible, by oceans of liquid air. If this be true, it should be possible to identify these gaseous lovers of intense cold by spectroscopic work with the planets and by a little investigation in terrestrial physical laboratories, like that at the University of Toronto, where equipment is available for experiments at 300 or 400 degrees below zero.

In England the active and efficient section of the British Astronomical Association which devotes itself, under the inspiring leadership of the Rev. Theodore E.. R. Phillips, to tlie study of the planet Jupiter, has observed a remarkable series of changes this year in that planet's appearance, changes which amateur star gazers can follow just now with even a small telescope. The'trouble with understanding Jupiter is that he changes his mask so often, for the markings visible on the planet seldorii remain two years the same. To explain why this is so is one of the tasks that the Rev. Phillips and his scientific flock have set themselves,

Perhaps the most remarkable of recent Observations on our neighbour worlds is that of Dr. E. M. Antoniadi, of Paris, on the inmost planet of all, the 6un-baked Mercury. Through an ordinary telescope Mercury is a mere bright disc, apparently featureless. Most observers have thought it as shrouded in eternal clouds. Through the great refracting telescope of the Meudon Observatory Dr. Antoniadi has identified, however, faint details which seem to bo permanent. If he is right, our idea of Mercury must undergo a change. We must imagine it a worl'd whose surface is solid, but almost perfectly smooth and featureless, a kind of celestial billiard ball. With the earth model of continents and ocean basins hold so insistently in front of us this featureless surface of a sister planet seems strange, but perhaps it is the earth that is unusual, not Mercury.