The Sun

The sun is Earth's source of light and heat. Without it, life as we know it could not exist!

Plants require sunlight to make food by photosynthesis. Using the sun's light, they convert water and carbon dioxide into sugars and oxygen. Animals, in turn, eat plants and are then eaten by other animals.

Even human beings are part of this food chain. Earth's food chain depends completely upon the sun.

The sun is Earth's source of light and heat. Without it, life as we know it could not exist!

Plants require sunlight to make food by photosynthesis. Using the sun's light, they convert water and carbon dioxide into sugars and oxygen. Animals, in turn, eat plants and are then eaten by other animals.

Even human beings are part of this food chain. Earth's food chain depends completely upon the sun.

Like most of the stars in the universe, the sun is a giant ball of hot, ionized gas, or plasma. The ball is not uniform, however. It is composed of several different layers. This special structure allows the sun to radiate so much energy.
To understand on how the sun produces its radiant energy,

click on each of the labeled areas.

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Name: Sun (Sol)
Type: Star, in the Milky Way galaxy
Mean Distance from Earth: 93 million miles (150 million kilometers)
Mean Diameter: 869,000 miles (1,400,000 kilometers)
Mass: 332,000 times Earth's mass
Density: 1.41 g/cm3
Gravity: Approximately 28 times Earth's gravity. It keeps the entire solar system - planets, moons, and millions of smaller bodies such as comets and asteroids - in orbit.
Composition: Mainly hydrogen and helium in a state of hot gas and plasma (ionized gas). The sun also contains approximately 70 other elements, but in minor quantities.
Rotation Period: Approximately 30 Earth-days