If you had needed to speak from space in a voice heard through time — inscribed in the mottled rock of a burnt-out asteroid you would have done so. The inside walls of the pitted husk inscribed with symbols and pictures. The paint could not glow, could not impart meaning because it had never been applied to the walls with careful hands, minds thinking forward to the souls that would sit on rusted canisters pondering the meaning of the undeciphered language.
The mild gravity of the rock trapped stray atmosphere, not enough to breath but enough to notice the occasional speck of dust float past the plexathane bubble of a suit's helmet. The writings were conspicuously absent as they littered other ruins -- something set this desolate rock apart from the rest of the locations that had been found, both on the primary inhabited planet and the outpost colonies scattered through the solar system. Nowhere could be found — any technology which would have allowed this civilization to settle other planets and asteroids.
Though some means of colonization must have existed, all trace of it was now gone. Hidden for a purpose certainly, as settling a colony could not have been a small undertaking and it was carefully cleaned up, the means of travel between the home world and the colonies carefully stowed away, hidden or at least obscured from careful inspection.
Teleportation was the favorite theory among lay people but the team of xeno-archaeologists dismissed that summarily, as did the physicists who were consulted in the matter by the science inquiry board — a commission of career diplomats and orphans — who sought to provide answers while collecting and collating all existing information about the recently discovered astro-location.