The Sun :
The Sun is only an average-sized star, but the energy it produces allows life to exist on Earth.
The Sun is a yellow dwarf star. Like all stars, it is a huge ball of spinning gas. Energy is produced in the Sun's core and travels to the outer part of the Sun. The high temperature and intense pressure create powerful nuclear reactions within the Sun's core.
Atoms of hydrogen smash together and fuse to form helium. This produces light and heat energy. The energy radiates outwards to the surface of the Sun which is called the photosphere.
The Speed of Light :
From the Sun's surface, light and other radiation travel to other parts of the solar system, including Earth. It takes 8 minutes and 17 seconds for this energy to reach our planet which is 150 million kilometers away from the Sun. The Sun's energy is essential for life on Earth.
It provides light for plants to grow — the basis of all food chains. The Sun also provides heat which creates our weather. The water cycle depends on this heat to bring about water evaporation — this forms clouds and rain.