J class gas giant moons
These two moons were orbiting a J class gas giant in a remote system of the Gamma Quadrant. In 2372, the USS Defiant entered the atmosphere of the Class J gas giant to rescue the crew of a Karemma ship. The Karemma were attempting to escape from two Jem'Hadar ships. (DS9: "Starship Down")
Parada IV moon
In 2369, the crew of the Starfleet runabout USS Yangtzee Kiang visited a moon that was determined to be the source of a narrow band subspace signal. It was orbited by a network of artificial satellites.
The moon was discovered to be a prison on which artificial microbes kept the prisoners forever alive to wage war with one another. These microbes resurrected Kai Opaka, but forced her to remain on the moon or die. Accepting her new situation as the will of the Prophets, Opaka remained behind. She hoped to teach the warring prisoners peace. (DS9: "Battle Lines")