Part of the show Sun Tans, Fission and Fusion
Scott in the USA asked:
Generally speaking, is the Sun really shrinking at a speed people should be worried about?
It's certainly shrinking because it's giving off matter into space all the time. It's known as the solar wind. But this is a tiny fraction of the mass of the Sun and it's certainly not going to evaporate off into space before it's used up all the fuel. One statistic I did hear is that it sheds one million tonnes per second. The numbers are so big that it's difficult to equate what they are, but it's the equivalent of the mass of a reasonable sized mountain per day.