The sun has more mass than any other object in our solar system.
In fact, the sun makes up more than 99% of all the mass in our solar
system. The sun is made of two gases—hydrogen and helium.
The sun is like a huge furnace that
turns hydrogen into helium.
Turning hydrogen into helium is
not easy. The sun turns hydrogen
into helium deep within its core, or
center. Here, the temperature is 15
million degrees Celsius.
Both hydrogen and helium are
types of atoms. Helium atoms are
larger than hydrogen atoms. The
intense heat and pressure in the
center of the sun squeeze together
hydrogen atoms. These hydrogen
atoms join to form helium atoms.
When this change happens, a large amount of energy is released.
Every second, the sun changes 600 million tons of hydrogen into
596 million tons of helium. The sun changes the other 4 million
tons of hydrogen into energy.
The energy that the sun produces in its core takes millions of years
to reach its surface. From here, the energy travels as light into
space. Almost all the sun's energy travels to places other than Earth.
Only half a billionth of this energy reaches Earth. Yet this tiny
fraction of the sun's energy is the source of energy for almost all life
on Earth.
Discovery Education Science
© 2007 Discovery Communications, LLC