In the interest of keeping us better informed, the U.S. Geological Survey has put out some of the latest vital statistics about our planet. They are these:
The weight of the earth, in the terms of its own gravitational pull upon its substance, is estimated to be 6 sextillion, 588 quintillion short tons. About 5.7 quardrillion tons of air cling to the planet's 197 million square miles of surface.
The earth's diameter at the equater is just under 7,927 miles. Because its rotation has forced more of its substance to the region of the equator, the earth's diameter at the poles is 7,900 miles. This slightly flattened shape is called an oblate spheroid.
The total volume of water in the world's oceans, ice fields, lakes, rivers, soilds, rocks and the atmosphere amounts to 326 million cubic miles. About 97 percent of all water is in the oceans. The biggest water storage trap is the Antartic ice cap, which covers 6 million square miles. If it melted at a uniform rate, it would yield about 6.5 million cubic miles of water, enough to feed the Mississippi River for 50,000 years. (A cubic mile of water equals 1.1 trillion gallons.)
The center of the earth lies nearly 4,000 miles beneath our feet. To date, man's drilling efforts have reached a depth of about 5 miles.
The planet consists of a skil-like outer crust, a mantle beneath that and an inner core. The crust, which ranges from 4 to 30 miles in thickness, makes up about 1 percent of the earth's volume. The mantle, which extends about halfway to the center, is about 84 per cent, and the core, which is believed to be 80 percent iron, 15 percent.
The earth is believed to be least 4.5 billion years old.