In Hindu scriptures, a Brahmastra (IAST: Brahmāstra, sanskrit: ब्रह्मास्त्र) is a weapon created by Brahma. It is sometimes known as the Brahma Astra(Astra means 'missile weapon'). As described in a number of the Puranas, it is considered the deadliest weapon. It is said that when a Brahmastra is discharged, there is neither a counter attack nor a defense that may stop it. It is believed that the Brahmastra never misses its mark and must be used with very specific intent against an individual enemy or army, as the target will face complete annihilation. It is believed to be obtained by meditating on the Creator in Hindu mythology, Lord Brahma, and used only once in a lifetime. Since Brahma is considered as the Creator in Hinduism, it is believed that Brahmastra was created by him for the purpose of upholding Dharma and Satya, to be used by anyone who wished to destroy an enemy who would also happen to be a part of his (Brahma's) creation. The target, when hit by Brahmastra, would be utterly destroyed.
It is believed that the Brahmastra is invoked by a key phrase or invocation that is bestowed upon the user when they are given this weapon. Through this invocation the user can call upon the weapon and use it via a medium against their adversary.
It is also believed that the weapon causes severe environmental damage. The land where the weapon is used becomes barren for eons and all life in and around that area ceases to exist. Women and men become infertile. There is severe decrease in rainfall and the land develops cracks like in a drought.
Empirical evidence in the form of melted granite slab at Kurukshetra in North India indicates production of intense heat- something only possible during a nuclear explosion. The after effects of the Brahmastra are very similar to a nuclear fallout and therefore people believe that this weapon might have some sort of nuclear component to it.
There are numerous instances within Hindu scriptures where the Brahmastra is used or use is threatened, including: