- For other uses, see Yridia.
The Yridia Nebula, also Yridian Nebula was a interstellar gas cloud located near Yridia, in the galaxy's Beta Quadrant. Radioactive gases within the nebula interfered with the operation of sensors. (DSC episode: "Lethe", ST reference: Stellar Cartography)
In December 2256, Sarek's Solkar-class cruiser traversed the nebula for a diplomatic summit with Klingon Houses at 55 Cancri. Logic extremist V'Latak, masquerading as Ambassador Sarek's aide, committed a suicide bombing, leaving Sarek injured and his cruiser wrecked and adrift in the Yridia Nebula.
Through a telepathic bond, Sarek's adopted daughter Michael Burnham learned of the calamity. Captain Gabriel Lorca allowed a rescue mission but the USS Discovery was unable to enter the nebula as the mycelium spores from its spore drive would interact catastrophically with the radiation. Discovery launched Class C shuttlecraft DSC 01 on a rescue mission. The shuttle crew was able to rescue the injured diplomat before their craft was overwhelmed by nebular conditions. (DSC episode: "Lethe")