Ancient contact
"Ancient contact" was the term used to describe the theory that Bajorans were able to reach the Cardassian system as early as the 16th century in ancient lightships.

As of the 24th century, the Cardassians had long disputed this theory, claiming that it was impossible that Bajorans were able to attain interstellar flight before they did. The theory was finally proven, however, in 2371, by Starfleet Commander Benjamin Sisko and his son Jake, who used a recreation of a lightship to duplicate the journey to Cardassian space. It was discovered that the naturally-existing tachyon eddies in the Bajoran system were able to propel the lightships to warp velocities, making the journey possible. ()
Bajor
History