Star Trek: 10 MORE Alien Encounters Before First Contact

10. Trill

First contact with the Trill occurred much earlier than Federation records would have us believe, even if the precise event has yet to be seen on-screen. Jadzia Dax changed the history books when she was accidentally thrown back in time, along with Sisko and Bashir, arriving in San Francisco in the early 21st Century.

This would have been contemporaneous to Tallinn's presence in LA, though San Francisco had its problems to contend with. For example, the Sanctuary Districts were powderkegs, threatening to explode at any moment. With Sisko and Bashir trapped inside one of them, Dax was forced to work alongside the locals to help them escape.

She was lucky. As she wasn't injured badly enough to require a closer look, she was able to pass her Trill markings away as a tattoo, therefore leaving the timeline unaltered. Sisko was not quite as fortunate, though, leading to his face becoming immortalised in the history books - for something other than starting the Dominion War.