In 2067 Earth launched the probe Friendship 1 carrying greetings and technical knowledge; in the Delta Quadrant it led to catastrophe for the world that found it.
Friendship 1 was sent from Earth to make peaceful contact with other civilisations. Its databanks held information on human culture and technology, including instructions for building antimatter reactors and communication devices.
The probe eventually reached a planet in the Delta Quadrant whose people used the knowledge to build antimatter weapons. A catastrophe followed, and the survivors lived in a nuclear winter, sick from radiation and bitter toward humans. In 2378 Starfleet sent Voyager to recover the probe, and Lieutenant Joe Carey was killed before Voyager helped restore the planet's atmosphere.