For now only a quick reference to Cannon site. These "cannon" folks are doing there truely amazing work with collecting all kind of "hidden" exploration stuff which was found by players: Wrecks, Abandoned settlements, hidden story sites, Guardians, Thargoids, huge space installations, mega-ships(generation ships) and others. They are it seems are also very quick with adding newest stuff found, so you can not do a mistake to look on theirs news pages regularly. There also tools used for examine mainly sound data (with hidden content) and more.