Otrin's homeworld
Otrin's homeworld was an unidentified M-class planet located in grid 310 in the Delta Quadrant; it was 132 light years from the nearest M-class planet, and approximately 30,000 light years from Earth. The planet was populated by a pre-warp civilization, until around 2248, when the Friendship 1 probe from Earth landed on the planet. 

The inhabitants reverse engineered the technology of the probe allowing them to develop their own antimatter weapons. Tensions rose between the rival native groups as they developed antimatter missiles which were only planned for use as defensive weapons. However the failure of a power grid in one the missile silos released antimatter into the planet's atmosphere, destroying most of the planet's surface, killing most of the planet's population, and poisoning the survivors with antimatter radiation, thus sending the planet into a state of nuclear winter. 

In 2378, the  neutralized the antimatter radiation, restoring the planet's atmosphere. ()

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de:Uxal
Homeworlds
Unnamed planets