Question: How long is it estimated to be when the sun looses it's energy?

Shreesha Bhat answered on 13 Mar 2015:

Hi Makin bacon, Its going to be a very long time, maybe trillions of years till its losses all of its energy, as over its lifetime, it has only lost about 0.05 percent of its mass. Although it looses a large amount of energy by the fusion process and solar winds, still the sun is big, and the amount lost is nothing compared to its size.

And yes, the Sun will eventually loose all its energy when it has no hydrogen for the fusion process, but till then, the temperature of the sun would have increased so much that in around 4 billion years, earth’s temperature can reach around 500 deg C, which will fry the earth, and the sun will turn into a giant red star. After it has blowed off a massive solar wind, it will die down to a white dwarf star.