Scientists believed that the planet Earth and the solar system were formed simultaneously. The solar system consists of the Sun, the planets, and other celestial objects, such as the moon, meteors and asteroids.

More scientifically, the basic idea is that the sun and the planets formed more or less simultaneously in a collapsing solar nebula. According to the theory, the solar system began with the collapse of a small part of a giant molecular cloud, which is the solar nebula—a solar nebula is a gaseous disk about the size of our present solar system. The collapsed small part eventually flattened into a disk-like shape as it continuously spun. The forces of gravity then squeezed most of the dust and gas into the center of this disk, making it hot enough to form a proto-sun, which eventually became the Sun. Around the Sun, a thin disk gave birth to the planets, moons, asteroids and other celestial bodies. After million of years and many collisions later, the disk settled into what we know and recognize as our solar system, which includes our planet Earth.

According to the modern theories, the planet Earth was formed about 4.6 billion years ago—although the oldest known crystal rocks are less than 4 billion years old.

Dimensions

Equatorial radius = 6,378.3 Km (3,963.4 Miles)

Polar radius = 6,356.9 Km (3,956.9 Miles)

Area

Land (29.22%) = 149 Millions of Sq. Km (57.5 Millions of Sq. miles)

Ocean (70.78%) = 361 Millions of Sq. Km (139.4 Millions of Sq. miles)

Total Surface area = 510 Millions of Sq. Km (196.9 Millions of Sq. miles)

Mass, Volume, Density

Mass = 5.976 x 10²⁷ grams

Volume = 1.08 x 10²⁷ cc

Density = 5.517grams/cc

Relief

Land:

Greatest height = 8848m

Ocean:

Greatest depth = 11035m