The Sun is a star in the middle of our solar system. The Earth orbits the Sun. The heat and warmth from the Sun maintains almost all life on Earth. About 74% of the Sun’s mass is hydrogen, and 25% is helium. The Sun is considered to be about 4.5 billion years old, which would make it about middle aged. Nuclear fusion in the Sun’s core fuses hydrogen atoms to form helium. In about 5.5 billion years the Sun will turn into a spiral nebula.
Ingibjörg Elsa Björnsdóttir „Sólin“, Náttúran.is: April 30, 2014 URL: http://xn--nttran-pta6r.is/d/2014/04/30/sol/ [Skoðað:Nov. 14, 2019]Efni má nota eða vitna í samkvæmt almennum venjum sé heimilda getið með slóð eða fullri tilvitnun hér að ofan.
breytt: June 12, 2014