In the Star Trek fictional universe the genesis device was an experimental terraforming device. It was introduced in Star Trek II: The Wrath of Khan, and we discovered that unlike existing terraforming methods, it could terraform an entire planet in hours. At the end of the film, we see the device detonated and create a new world from scratch out of the gas and dust of the Mutara Nebula.
Star Trek III: The Search for Spock featured this world. We discover that one of the device's creators, Dr. David Marcus, son of Captain James T. Kirk, had, true to his father's legendary tendency to "think out of the box" when at a loss, had secretly utilized the dangerous and unstable substance "protomatter" in order to obtain functionality of the Genesis prototype.
This rendered the device's effects similarly unstable and short-lived, and hence the experiment a failure; however due to its destructive power beyond any known weapon, the device afterward became coveted for military purposes. The Genesis Device has not been seen since, and it is generally assumed its plans are destroyed or being kept under lock and key, or else banned by treaty.
