Astronomy in 1909.

Progress, Volume V, Issue 6, 1 April 1910, Page 202

Astronomy in 1909.

The year 1909 is astronomically memorable for the return of Halley's famous Comet. On September 11th last. Dr Max Wolf of Heidelberg discovered this historic wanderer upon one of his photographic plates in almost the exact position which the calculations of Cowell and Crommelin called for — a feat which may be regarded as a triumph of mathematical astronomy. The comet will pass herihelion on April 20th, and will be a conspicuous object in the western heavens after sunset about the middle of May, at which time the earth will pass through a portion of the comet's tail, and the comet itself will cross the sun's disk. The reappearance is therefore of exceptional interest, because it will give astronomers an opportunity of obtaining much valuable information as to the comet's structure. The year was further signalised by the discovery of another comet by Mr. Daniel of the Princeton Observatory — the third he now has* to his credit. On September 24th, 1909, an opposition of Mars occurred — the most favourable which astronomers can possibly Have for another fifteen years. On that date the planet was distant 35,500,000 miles. Naturally, the old question of Martian habitability was revived. Prof. Pickering, in order to settle it once and for all, pro-

posed a method of signalling by mirrors, and Prof. "Wood of Johns Hopkins University, suggested a method of "winking" by means of black cloths on reels. Neither astronomer probably believes in intelligent life on Mars, but was actuated solely by a desire to close a wearisome, perennial debate. The theory of habitability depends very largely upon the presence of water on Mars. Dr Campbell, director of the Lick Observatory, made a careful comparison last year of the spectra of the moon and Mars. He found that there was no appreciable difference between the two, from which he infers that Mars must be practically waterless, and therefore as dead as the Moon Mr. Very, of Prof. Lowell's staff, on the other hand, has arrived at a directly opposite conclusion. So far from being decided, the old question is therefore more alive than ever. There were two eclipses of the Sun and two of the Moon. The lunar eclipses were both total and occurred on June 3rd and November 26th. The eclipses of the Sun, occurring on June 27th and December 12th, were respectively central and partial.