the Sun is going to run out of fuel in about 7-8 billion years. What will happen to the planets then, especially to Earth? Research suggests, if tidal forces are taken into account, then the Earth is likely to evaporate when the Sun treads towards its death ( Icarus , Vol 151, p130).
The Sun belongs to a class of stars called the main sequence stars. Thermonuclear fusion reactions in their core convert hydrogen atoms into helium atoms and in the process releases a lot of energy. This energy holds up the Sun against its own gravitational force. In the absence of any energy generation, the material in the Sun would collapse into the core. This very energy also provides us with our life force on Earth.
And though the sun is massive, it holds a limited volume of hydrogen. At some point of time all the hydrogen is bound to be converted into helium. At this point, the Sun will enter the