COMETS AND THEIR TAILS.

Taranaki Daily News, Volume LII, Issue 348, 26 March 1910, Page 10

COMETS AND THEIR TAILS.

Although scientists have not yet discovered exactly what a comet consists of ytheir observations have lei to some remarkable revelations. A comet may be described as a definite point of nucleus, surrounded by light, with a luminous train preceding or following. The generalj>pinion of astronomers seems to be thrftT the point is possibly solid, or at any rate condensed, the tail consisting of minute particles floating in a gaseous envelope, and the whole being ■whirled round the sun at a rate which in some cases reaches as much as 370 miles a second.

The comet 01 1910, for which everyone is looking at the moment, is a email one compared with, others which have been observed in previous years. The tail is said to be close on 28,000 miles in length, but in 1882—the last occasion on which a bright, naked-eye comet was seen—it was estimated that that comet had a tail which extended in space to the vast distance of 200,000,000 miles front the head, though, owing to foreshortening, it did not appear to be that extraordinary length. The tail was strongly forked, and a singular and puzzling feature of the comet was that a small cone, or envelope, computed to be 4,000,000 miles in length, also extended towards the sun.

Sir W. H. M. Christie, the Astrono-mer-Royal, ha 9 collected some striking facts with regard to comets' tails. He •ays that the tail of the comet in 1801 was 40,000,000 miles long; that of IGBO had a tail 60,000,000; that of 1811, which was visible ior seventeen months, over 100,000,000; while the visitor of 1543 showed a tail in the evening twilight of 65deg., or about 200,000,000 miles in length—which exceeds the diameter of the earth's orbit.

,n "5bE the least amazing feature of tkese bodies is their wonderful velocity when near thes un. The comei which Newton saw in 1680 was travelling at the rate of 250 miles a second, and that of 1843 at 370 miles a second. The earth in its orbit moves at 18y 2 miles a «econd.

Apropos of the assertion frequently made, that should one oi these comets touch the earth, it appears that already we have passed through the comet's tail. Sir W. Chritie thinks that in 1861 we passed through the outer part of a comet, particles of which appeared as a shower of falling stars; while other scientists also affirm that we hace come into contact with comets, and that there is not the slightest need to worrk or iniure against them in view of damage.,