For the episode of Star Trek: Enterprise, see "Rogue Planet".

A rogue planet is a planet that has broken out of its orbit around a star. However, such a planet may still be capable of supporting life due to geologic activities on it, such as hot gases venting from its interior, forming oases where lifeforms can thrive. The lack of a sun caused rogue planets to exist in a state of perpetual night.


The Founders' homeworld, a rogue planet in a nebula

The Founders' homeworld in the Omarion Nebula in the Gamma Quadrant was an example of such a planet. (DS9: "The Search, Part I", "The Search, Part II", "The Die is Cast")

In the TOS: "The Squire of Gothos", Spock described Gothos as a "lone planet" implying it was rogue planet. However, Kirk later ordered the crew to take the Enterprise beyond "the point at which we entered [Gothos's] solar system", implying it orbited a star instead.
According to the non-canon reference book Star Trek Maps, Trelane's planet of Gothos mentioned in TOS: "The Squire of Gothos" also is a rogue planet.

Dakala, a rogue planet

In 2151, Captain Jonathan Archer and the crew of Enterprise NX-01 discovered a rogue planet named Dakala that was used as a hunting ground by the Eska, whose people had come to the planet for nine generations to kill the indigenous species. Using sensing cloaks which prevented them from being detected, the Eska were able to successfully track down their prey. As it turned out, this "prey" was in fact a sentient species of telepathic shapeshifters, called wraiths by the hunters, who were being killed by the Eska for sport. (ENT: "Rogue Planet")

Vidiian planetoid, Phage

A rogue planetoid

In 2371, the USS Voyager discovered a rogue planetoid that they thought contained dilithium deposits. In reality, however, it was being used by the Vidiians as an organ lab. (VOY: "Phage")

By 2373, Q had taught his son how to knock small planets out of orbit. (VOY: "The Q and the Grey")