Genesis was a planet created from the gaseous matter of the Mutara Nebula as a result of the detonation of the Genesis device in 2285. Because of David Marcus' use of unstable protomatter in the device, the planet degraded into an unlivable rock later that year. (Star Trek II: The Wrath of Khan; Star Trek III: The Search for Spock) After Captain Spock's death aboard the USS Enterprise, his photon tube coffin soft-landed on the planet where the Genesis effect resurrected his body, though he aged rapidly in synchrony with the planet's unstable shifts. (Star Trek III: The Search for Spock)