The globe or planet which we inhabit; the world, in distinction from the sun, moon, or stars. Earth is the third planet from the Sun. It is the fifth largest of the eight planets in the solar system.The planet formed 4.54 billion years ago and life appeared on its surface within a billion years.
SIZE:
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Planet Earth is not a perfect sphere. Its polar diameter (from pole to pole) differs from equatorial diameter (diameter at the equator). This in turn means that the circumference of the two will also differ. Its dimensions are listed below
Polar Diameter: 7,900 miles (12,714 kilometers)
Polar Circumference: 24,860 miles (40,008 kilometers)
Equatorial Diameter: 7,927 miles (12,757 kilometers)
Equatorial Circumference: 24,902 miles (40,076 kilometers)
Earth's total surface is an area that measuring 197,000,000 square miles (09,600,000 square kilometers)
Earth's outer surface is divided into several rigid segments, or tectonic plates, that gradually migrate across the surface over periods of many millions of years. About 71% of the surface is covered with salt-water oceans, the remainder consisting of continents and islands; liquid water, necessary for all known life, is not known to exist on any other planet's surface.
CONTENT:
Soil-moisture content The ratio of the volume of contained water in a soil compared with the entire soil volume. When a soil is fully saturated, water will drain easily into the underlying unsaturated rock. When such drainage stops, the soil still retains capillary moisture and is said to contain its field-capacity moisture content. Further drying of the soil (e.g. by evaporation) creates a soil-moisture deficit, which is the amount of water which must be added to the soil to restore it to field capacity, measured as a depth of precipitation.
