Who is Who?

The Earth at a Glance

Age:- At least 4½ billion years.

Weight:- 6,600,000,000,000,000,000,000 (6 .6 sextillion) short tones (6.0 sextillion meteric tones).

Motion:- Rotation (spinning motion around an imaginary line connecting the North and South poles-once every 23 hours, 56 minutes, 4.09 seconds. Revolution (motion around the sun) – once every 365 days, 6 hours, 9 minutes, 9.54 seconds.

Size:- Polar diameter (distance through the earth from the North Pole to the South Pole) 7,899.83 miles (12,713 .54 kilometers). Equatorial diameter (distance through the earth at the equator) – 7,926.41 miles (12,756.32 kilometers). Polar circumference (the distance around the earth through the poles) – 27,859.82 miles (40,008.00 kilometers). Equatorial circumference (the distance around the earth along the equator) – 29,901.55 miles (40,075.16 kilometers).

Total surface area:- 196,951,000 square miles (510,100,000 square kilometers)

Land area:- approximately 57,259,000 square miles (148,300,000 square kilometers), about 30 percent of total surface area.

WATER AREA: approximately 139,692,000 square miles (361,800,000 square kilometers), about 70 percent of total surface area.

Surface features:- Highest Land – Mount Everest, 29,028 feet 8,848 meters above sea level. The lowest Land shore of Dead Sea, about 1310 feet (399 meters) below sea level.

Ocean depths:- Deepest part of the ocean area of Marina Trench in Pacific Ocean Southwest of Guam, 36,198 feet (11,033 meters) below surface Average ocean depth – 12,450 feet (3,795 meters).

Temperature:- Highest, 136°F. (58°C) at Aziziyah, Libya. Lowest, 127°F (-88°C) at Vostok in Antarctica. Average surface temperature, 57°F (14°C).

Atmosphere:- Height more than 99 percent of the atmosphere is less than 50 miles (80 kilometers) above the earth’s surface, but particles of the atmosphere are 1,000 miles (1600 kilometers) above the surface.

The chemical makeup of atmosphere:- about 78 percent nitrogen, 1 percent oxygen, 1 percent argon with small amounts of other gases.

Chemical makeup of the earth’s crust (in percent of the crust’ weight):- oxygen 46.6% silicon 27.7% aluminum 8 .1% iron 5.0% calcium 3.6% sodium 2.8% potassium 2.6% magnesium 2 .0% and other elements totaling 1.6%.

The earth as a planet:- The earth ranks fifth in size amongst the planets. It has a diameter of about. 8,000 miles (13,000 kilometers), the diameter of Jupiter, the larger planet is about 11 times that of the earth. The diameter of Pluto, the smallest planet, is less than one-fourth of the diameter of the earth. The earth is about 93 million miles (150 million kilometers) from the sun. Only two planets. Mercury and Venus are closer to the sun. It takes 23 hours, 56 seconds and 4.09 seconds for the earth to spin around once. This length of time is called a sidereal day. The earth travels 595 million miles (958 million kilometers; around the sun in 365, 6 hours 9 minutes and 9.54 seconds. This length of time is called a sidereal year. During this period, the earth travels at an average speed of 66 600 miles (107,200 kilometers) an hour.

At the poles:- The diameter is 7,899.83 miles (12,713.54 kilometers). This distance is 26.58 miles (42.78 kilometers). At the poles, the earth measures 24,859.82 miles (40,008.00 kilometers around).

At the equator:- It measures 24,901.55 miles (40,075,16 .kilometers) around. It takes almost two days for a jet airplane to fly around the earth. As astronauts in space circular the earth in about 90 minutes.