It is the Latin motto of Starfleet Academy, meaning “From the stars knowledge”. The ancient Romans usually did not use verbs in inscriptions, so it would be better supplemented to “Knowledge comes from the stars”. If you miss the comma of “Ex Astris, Scientia” as in the official Academy badge, this is one more thing the Romans would have omitted. I have chosen this motto to express the relation between the fiction in Star Trek and real science. You may have noticed that my site logo (upper left corner of this page) is not only reminiscent of a communicator badge, but also represents the title, since the knowledge (Starfleet arrowhead) emerges from a star.