THE MYSTERY OF COMETS.

Te Aroha News, Volume XXVII, Issue 43214, 13 August 1907, Page 4

THE MYSTERY OF COMETS.

The comet lately discovered by M. Flammarion, an 1 astronomer as fanciful as he is illustrious —has excited much interest, especially as the comet mav be seen from both hemispheres. Astronomers have -weighed and measured) the heavenly bodies, and have calculated their movements to the tenth of a second of time. B!y the aid of the spectroscope they have analysed tlie principal chemical constituents of the suns of distant systems—the very light ‘which they analyse having occupied many years in transit to our earth —'but the comet is still a mystery as iprofound as it is fascinating. Its orbit can—sometimes—be calculated; its passage round the sun marked), and the characteristic phenomena noted; but of its constitution, and the immense forces which develop, sometimes in a few hours, its magnificent “tail,” and which, more marvellous still, whisk that tail, which may be ai million miles in length or more, to the opposite point of the compass with the speed of light, science can tell us nothing. Planetary attraction may vary the orbit and period by acceleration or retardation, and the passage round the sun is a critical experience attended with much risk. For instance, Biela’s comet, in 1845-6, met with a grievous accident. In full sight of men it parted asunder. Its return in 1852 was as “twins,” al million and a half miles apart, and returned no more. But when the earth passed the spot where it! should have been, some seven years later, there was a smiall shower of meteors, possibly from the remains of the nucleus. A! comet consists of three parts —ai nucleus, which shines like a small star, and apparently is a cluster of masses of solid matter, and a. “coma,” or hazy sphere surrounding, the nucleus, the two forming the “head.” This is all that is at first seen. As lit approaches the sun with accelerating rapidity, a tail is thrown out in the direction opposite to the sun, which, in the case of a great comets soon occupies millions of miles, and shines with ai milky light. It has no discoverable weight, ind is so marvellously attenuated, 'hat the stars are seen through thou-j «nds of miles of this luminous veil. As the comet sweeps round the sun, sometimes in close proximity the unknown repulsive foreie which the luminary exerts turns the tail still in the opposite direction, and the telescope reveals torrents of luminous gas issuing from the head. Luminosity usually implies heat or combustion —but what can : maintain heat in so widely diffused a vapour at such immense distances from its source? There is as yeti no reply. Arthenius the great Danish' astronomer -and physicist, has lately propounded certain comprehensive theories, including the Zodiacal) light and! other as yet. unclassified phenomena of the heavens—he may perhaps have found the clue. Flammarion's Comet, in its course, may reveal new and significant facts. There may yet be a satisfactory theory of these interesting bodies; but in this department science has still to admit that there are certain'things in creation which it has* so far tojeen! unabl© to unveil. 1 $ ’■ . F '