How Is Carbon Formed?

Life-Giving Stars

• The elements -- including carbon -- make up everything around us, and they originated in stars. Elements do not appear in stars spontaneously; instead, they are formed. Stars begin as cold clouds of dust that turn into mainly hydrogen molecules. Then gravity goes to work to form a star, compressing the hydrogen molecules into a core and causing them to heat up. At the core, energy is then created from the fusion of hydrogen to helium.

Nuclear Fusion

• Nuclear fusion is the process in which atomic nuclei of the same charge bind to create more dense nuclei. The process of nuclear fusion uses up the hydrogen molecules at a star's core and steadily increases the helium content. Fusion creates an intense amount of energy, rendering matter in a plasma state that is neither solid, gas or liquid.

Birth of Carbon

• Once a star uses up all of the hydrogen at its core through nuclear fusion, all that is left is helium. The outer edges of the star expand, creating what is called a red giant. Hydrogen fusion then starts around the outer edges of the core until only helium is left at the outer edges. Then helium fusion begins, and the star begins to shrink, or die. It is at this stage where carbon is born, resulting from the nuclear fusion of three helium atoms.

Carbon on Earth

• Carbon is found everywhere on earth, carried here from numerous stars that have collapsed or exploded. There are a variety of carbon allotropes (two or more physical forms of an element) on earth as well, and these include diamond, coal, graphite, fullerenes, and glassy carbon, to name a few. Carbon is even found in the atmosphere, where it is continually made through a nitrogen reaction. Because the bombardment of cosmic rays is fairly consistent, carbon is continuously produced.