How hot is the Sun? The temperature of the surface of the sun is believed to be at least 10,000 degrees Fahrenheit. In such intense heat every substance known on earth would be reduced to gas. This is one of the reasons why it is thought that the sun is not solid, but is chiefly made up of various forms of gases. If the light of the sun were to be shut off from the earth we should perish from cold and starvation. If only 10 per cent of its heat was lost large parts of the earth would become frozen and desolate wastes.
(We now know it is chiefly made up of Hydrogen and Helium)