Page 43 - Curriculum Visions Dynamic Book. To close the book, close the tab.
P. 43
Sun, the
Chromosphere. This is the outer edge of the visible Sun which can be seen shining with a reddish glow during an eclipse. In this region very fine jets of gas shoot out from the Sun at speeds of up to 30,000 km/hr.
Photosphere. This is the visible surface of the Sun, a surface layer of gases where convection cells bubble to the surface.
Radiation zone. Here the gases are so dense that no gas molecules can move. Heat is lost toward the surface by radiation.
Convection zone. This makes up the outer third of the
Sun. Here the temperature is “only” about 1 million °C, and the gases turn over and over by convection like a liquid heated in a pan from below. The Sun’s gigantic magnetic field is probably formed in
this region.
Core. The most dense region of gases has a temperature of about 15 million °C. It is the region where most of the energy is generated. The energy-making processes have gone on for about five billion years. Scientists believe that in about five billion years’ time the Sun will have lost enough hydrogen for it to begin to die.
43
