Thermonuclear fusion is a way to achieve nuclear fusion by using extremely high temperatures. There are two forms of thermonuclear fusion: uncontrolled, in which the resulting energy is released in an uncontrolled manner, as it is in thermonuclear weapons such as the "hydrogen bomb", and controlled, where the fusion reactions take place in an environment allowing some of the resulting energy to be harnessed for constructive purposes. This article focuses on the latter.Nuclear fission is a nuclear reaction in which a heavy nucleus splits into two lighter nuclei, releasing a considerable amount of energy.

In the 20th and 21st century, nuclear fission was used as a power source in nuclear fission reactors, but also as a devastating weapon. Nuclear fission produces beta radiation. (Star Trek IV: The Voyage Home; Star Trek: First Contact; DS9: "Little Green Men")

The thought of nuclear fission taking place in a planet's atmosphere shocked Quark and Rom when they learned about it from Nog in 1947. (DS9: "Little Green Men")

Unless otherwise stated, the content of this page is licensed under Creative Commons Attribution-ShareAlike 3.0 License