Meteorites

With tremendous, white-hot roar a small meteorite recently rushed from the skies and smashed into southwest Africa. Last week Harvard's Dutch-born Astronomer Willem Jacob Luyten examined the sky-piece and found it the biggest thing of its kind yet observed by Science. It measures 10 by 10 by 14 feet and weighs between 50 and 75 tons. Hence it is bigger than the record 36 1/2 ton meteorite found on the edge of Greenland by the late Polar Explorer Robert Peary and given to the American Museum of Natural History.

Certainly much larger is the yet unfound meteorite which ripped into northeastern Arizona an unknown number of years ago and formed Meteor Crater (also called Coon Butte) about two miles east of Canyon Diablo. That meteorite ploughed a circular hole 4,000 ft. in diameter. 600 ft. deep, and threw up a rim 150 ft. above the surrounding plain. For years miners have been trying to locate its buried mass, for the sake of its iron and nickel.*

Even larger must be the mass that struck the-Province of Yenisei, Siberia, in 1908. The place had been a forest. It is now a bare area churned up for several miles. Russian scientists, led by L.A. Kulik, tried vainly to dig up even fragments of the meteorite. They were buried too deeply. This year the Russians may explore again.

Of meteors and related effluvia has the earth been compounded. A billion or more years ago, according to the planetesimal theory of the late Geologist Thomas Chrowder Chamberlin (TIME, Nov. 26). a star passed near to the sun, and by tidal action sucked the gases of a great sunburst out into space as a monster twirling gas mass./- The gas broke into eight main puffs which gradually coalesced into the eight planets--Mercury, Venus, Earth. Mars, Jupiter, Saturn, Uranus and Neptune. The first four are now more or less solid, the others very gaseous, Jupiter, the largest, being 1,000 times greater than Earth.

As these eight planets swerved through the eons around the Sun they attracted similarly compounded planetesimals, meteorites, chondrulites. The process of accretion still goes on. Earth within human history has not been struck by (i. e., has not attracted) a planetesimal. But each day at least one meteorite lands, and 20,000,000 chondrulites whiz into the earth's atmosphere. They are the shooting stars seen most often in November (the Leonid shower), in August (the Perseid shower) and in April (the Lyrid shower).

Thus the planetesimal theory thought out by Chamberlin 30 years ago and elaborated with his Chicago University associate, Astronomer Forest Ray Moulton.

Professor Moulton, since last year a director of Utility Power & Light Corp. (Chicago), has been conducting an acrimonious, unended debate with Harold Jeffreys, English astronomer. Professor Moulton charges British astronomers with belittling Chamberlin's pioneer work on the planetesimal theory and insinuating that they accomplished its real development. Professor Jeffreys pooh-poohs Prof. Moulton's charges, says brusquely that Prof. Moulton "has been asleep for 20 years."

*Meteorites are of three main types: siderites. metallic; aerolites, stony; siderolites, mixed stone and metal. The Southwest Africa meteorite is 90% iron, 10% nickel.

/-Sunbursts are going on all the time. They resemble clouds from active volcanoes. To men they are visible as sun spots and have some, yet unascertainable, relation to the Aurora Borealis.