Drema IV
The surface of Drema IV
Drema IV is an M-class planet located in the Selcundi Drema sector. It is inhabited by a pre-warp civilization called the Dremans. It is the only habitable planet in the sector, as every other planet had been destroyed by tectonic stresses.
In 2365, the USS Enterprise-D became the first Starfleet vessel to survey the planet. It was discovered that the planet was geologically unstable, due to dilithium lattices beneath the planet's crust, that translated geothermal energy into mechanical force.
During the mission, Lieutenant Commander Data detected a low-level RF signal sent by a Dreman girl, Sarjenka. She asked if there was "anyone out there", prompting Data to respond. Data informed Captain Picard of his contact with Sarjenka after he learned that Drema IV was on the verge of self-destruction. Because Data's actions violated the Prime Directive, Picard initially ordered Data to sever all contact with the surface. However, when he heard Sarjenka's voice, telling Data she was afraid, he decided that they must act.
The survey team, headed by acting Ensign Wesley Crusher, suggested that harmonic vibrations emitted by class-1 probes fitted with resonators fired into the planet would shatter the planet's dilithium lattices and thus alleviate the tectonic stresses tearing the planet apart. The plan was a success and the planet was saved from destruction. (TNG: "Pen Pals")