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Physical characteristics of Earth

Earth

Earth is a rotating sphere that orbits the Sun. The Earth's axis of rotation is at a constant tilt with respect to its orbit around the Sun, resulting in the change of seasons. The physical characteristics of the Earth include its size and composition.The Earth also has gravity and magnetic force fields.

Physical characteristics Physical characteristics include shape, size and composition.

Spherical in shape

Just as the Sun and Moon appear as spheres, so too is the Earth spherical in shape.

Size The diameter of the Earth at the equator is 12,756 km (7,926 miles), and its circumference or distance around the Earth at the equator is 40,075 km (24,901 miles).

Composition The composition of the Earth consists of the solid and liquid portion and the atmosphere or gaseous portion.

The percentage composition of the Earth's solid, liquid and gaseous materials (by mass) is:

Iron 34.6% Oxygen 29.5% Silicon 15.2% Magnesium 12.7% Nickel 2.4% Sulfur 1.9% Titanium 0.05%

Atmosphere The atmosphere of the Earth consists of 79% Nitrogen (N2), 20% Oxygen (O2) and 1% of other gases such as Carbon Dioxide (CO2).

Force fields The Earth has two major force fields: gravity and magnetism.

Gravity Gravity is the force at a distance that attracts objects of mass toward each other. The force of gravity from the Earth holds down our atmosphere, oceans and everything else.

Magnetic field The Earth is like a giant magnet with a magnetic pole near the North Pole and the opposite near the South Pole. The rotation of the Earth and the fact that the core of the Earth is made of iron are major factors in creating the magnetic field.

Summary The Earth is a rotating sphere that orbits the Sun. The axis of rotation of the Earth is at a constant tilt with respect to its orbit around the Sun, thus resulting in the change of seasons. Iron and oxygen make up 65% of the Earth's mass. The Earth also has gravity and magnetic force fields.