THE EARTH Estimated Weight (mass) (5,940,000,000,000,000,000,000 metric tons) Estimated Age 4.6 billion years Current Population 6,446,131,714 Surface Area (510,066,000 sq km) Land Area (148,647,000 sq km) 29.1% Ocean Area (335,258,000 sq km) Total Water Area (361,419,000 sq km) 70.9% Type of Water (97% salt), (3% fresh) Circumference at the equator […]