Our Sun

  • Our sun is a star, composed mostly of hydrogen and helium.
  • The sun is about 150 million kilometres from Earth. This is a distance of one astronomical unit. Light from the sun takes only a few minutes to reach the Earth.
  • The sun's temperature varies from 6000oC at the surface to 16000000oC at the core.
  • The sun rotates approximately every 30 days.
  • Sunspots are darker, cooler parts of the sun which rotate approximately every 11 years.
  • Solar Flares are explosions of hot gases from the surface. These send off electromagnetic radiation that causes auroras in Earth's night sky, and disrupts radio transmission.
  • Solar Prominences are arches of hot gases that are seen on the sun's surface.
  • The sun makes its energy from nuclear reactions called Nuclear Fusion, a process in which 2 hydrogen nuclei join to make a larger helium nucleus. This process gives off huge amounts of heat and light energy.
  • The sun's age is about 4.5 billion years. There is probably enough hydrogen to fuel nuclear fusion reactions for another 4.5 billion years, so the sun is probably half-way through its life.