At some point after 2248, and decades before 2370s, Otrin's species learned of antimatter technology from the Human probe Friendship 1, launched in Earth year 2067. Their early experiments with antimatter particles resulted in a massive antimatter explosion, which rendered their homeworld virtually uninhabitable after experiencing a nuclear winter. In 2378, the USS Voyager neutralized the antimatter radiation, restoring the planet's atmosphere to normal levels. (VOY: "Friendship One")