Eridios was a planet located in either the Alpha or Beta Quadrants of the galaxy.
In 2255, the planet was the site of a disaster that threaten all of space-time. To contain the threat the USS Enterprise destroyed all life on the planet. These events led to the creation of Starfleet's General Order 24. (Ship Recognition Manual, Volume 4: Starships of the Original Series Era)
External link[]
- Eridios article at Memory Beta, the non-canon Star Trek wiki.