Survival of the Fittest
First discovered on Saturn’s moon Pandora (hence the name) these gates have been found throughout the solar system. They form wormholes to places outside our solar system, and allow transhumanity to spread out among the starts.
No one knows who constructed them, though the best bet is that it was the TITANs. It is theorized that when they disappeared they traveled through the pandora gates to places unknown, and for reasons unknown. So, if you go Gatecrashing and run into the TITANs don’t say I didn’t warn you.