P9X-391 is now an uninhabited planet of sand and wind. Only a few ruins of an ancient civilization remain, largely eaten away by sandstorms. Evidence suggests that the planet was once some sort of science outpost or observatory built by the Ancients. In an underground chamber just below the main section of the ruins, SG-1 discovered an inter-dimensional device which was brought back to Earth.
Cross Reference: Ancients, Inter-Dimensional Device, Inter-Dimensional Insects
Episode Reference: Sight Unseen