Hi John,

The lifetime of a star depends on how massive it is. We expect that stars like our Sun will have a lifetime of around 10 billions years. The Sun is currently about 4.5 billions years old. Towards the of the Sun's life to will turn into a red giant star. The radius of the Sun will expand to at least 200 times it's current size which is just about out to the distance of Earth, but that isn't going to happen for another 5 billion years!

The Sun's energy comes from the nuclear fusion of Hydrogen happening in the core. The energy from the fusion in the core takes 50 million years to reach the surface of the Sun and for us to feel the effect. So if you turned of the energy in the core suddenly, it would take us 50 million years to feel the effects.

One thing that is in the news a lot are solar flares and coronal mass ejections. These are big explosions on the Sun that release lots of energy into space and towards Earth. However here on Earth we are protected by the Earth's magnetic field. It helps shield us from the high energy particles coming from flares and coronal mass ejections. However satellites in space and astronauts can be harmed as a result of flares and CMEs.

I hope that helps answer the question.

Hazel

Hi, John,

You might want to check out another project of ours called Calendar in the Sky. The project's website addresses many misconceptions about the supposed end of the world this yearr, especially regarding the predictions of the Maya.

There are lots of articles, pictures and movies.

Hope you enjoy it!

-- Karin