STAR DUST

Grey River Argus, 23 April 1925, Page 2

STAR DUST

(By

W. J. C. Murray,

M.8.A.A., in the

“Daily Mail”)

lt estimated that over 12,001' tons of star .lust falls annually on the earth This dust may have originated from a comet, or be the fragments of two great stars which crashed in their orbits ages ago, or the result of some other celestial eatastro phe. Usually it reaches the earth’s surface as fine dust, Lvf it first encounters our atmosphere in the form of a metoor, or more familiarly a "snooting star. ’ ’ These “shooting stars” are small masses, usually of iron or stone, either following in the orbit of a comet long -inco dispersed or circulating in interplanetary space. •. - on our atmosphere xxHh a terrific xodocitv, become incandescent through friction with Ihc air, and in a few seconds are either consumed or they explode with great force, and the ashes fall to the earth as s tar dust. Tn viexx- of the tremendous number of meteors that hourly plunge into the earth’s atmosphere. 12.000 tons annual ]y is a v°ry moderate estimate. The average number of meteors vis'l)!e hourly in the xvhole night-sky f-om a fixed position varies b •tween 30 and 60. Rut as only those within a few hundred miles are visible to an observer, the computed total is not foxver than sex oral millions dailv. Shooting stars very much in size, but assuming the average xveight to he e quarter of an ounce, then the fall of star dust is close upon 100 i.ms exerv twenty-four hours. This fall is continuous throughout the vear. Tt is at a minimum noxv. ami reaches a maximum in autumn. Yet it would tube a tliousnnd in:ll'on years before sufficient iimlerial find fallen to o'--.rl::y the earth to a depth O-c::si<,n:i !ly meteors are so Inrge that they reach the earth’s surf.ee before 1 hex- are entirely consumed. If their flight has seen by one or two compoteut observers. 1 :)■• place xxhere they lie luirieil can !>•’ determin'd and their composition di.--<o\-ered. Limestone and magnesia, iron, ami sometimes nickel are found. biF <•> far no element not known Io earth .'.as been diseoxerod. The '!:>•■ oust x'.liidi rolle'-i- •" .or shelves r.nd cornices rout •: 11:< a -nc'U p.-reentnge of star ‘bi>T. But r.mong the largest 'pieces f ‘f star dv.st ’ t nat e.axe yet. been recordocl is that which fell in Greenl.-ir.l :in,l v:is eeuveyod by Comninnder Peary to N.-w York. It weighed 26! tons.