What Is It Like Down There?
WHILE men have walked on the moon, we know little about the depths of our earth. The “ground” we tread on is but a “stony skin,” or crust, about 20 miles (32 kilometers) thick. Below this are: the mantle, the outer core and the inner core. Man has never made it all the way through the crust, for which we should be thankful.
The heat within the earth grows progressively intense; at the center it may be as high as 9,000 degrees Fahrenheit (5,000 degrees Celsius). While the outer core is said to be “liquid metal,” scientists think that the inner core of iron and nickel is solid, apparently because of the extreme pressure.