Ad astra is a Latin phrase meaning "to the stars". The phrase has origins with Virgil, who wrote in his Aeneid: "sic itur ad astra" ('thus one journeys to the stars')^[1] and "opta ardua pennis astra sequi" ('desire to pursue the high[/hard to reach] stars on wings').^[2] Another origin is Seneca the Younger, who wrote in Hercules: "non est ad astra mollis e terris via" ('there is no easy way from the earth to the stars').^[3]

Ad is a Latin preposition expressing direction toward in space or time (e.g. ad nauseam, ad infinitum, ad hoc, ad libidem, ad valorem, ad hominem). It is also used as a prefix in Latin word formation.^[4]

Astra is the accusative plural form of the Latin word astrum 'star' (from Ancient Greek ἄστρον astron 'star', from Proto-Indo-European *h₂ster-).^[5]