Aschen Prime

Aschen Prime, also known simply as Aschen and designated P4C-970 by the Tau'ri, was the homeworld of the Aschen and was also home to a Stargate.

In 2000, a written note with Jack O'Neill's handwriting and blood emerged from Earth's Stargate, reading: "Under no circumstances go to P4C-970. Colonel Jack O'Neill." Unknown to the SGC, the note was sent from the year 2010 in an alternate timeline in which the Aschen covertly sterilized Earth's population. General Hammond subsequently declared the planet off limits to the SGC; its address was locked out from the planet database and all contact with it was forbidden.