Origin: a planet near the center of the Galaxy. Galactic explorers (pronounced "sy-THEER-ee-uns") who "stay at home" rather than travel, and bring what they seek to their home world near the center of the Milky Way via instructions encoded in probes.
Incompatible with Federation computers aboard the Argus Array and a shuttlecraft, one probe "reprogrammed" Barclay to bring the U.S.S. Enterprise NCC-1701-D. They then greeted the ship with an interactive hologram on the bridge and reconfigured Barclay to normal. The information they pass on will take decades to examine. The image projected is human-like, bearded and elderly, except for a small blue patch centered on the forehead.