Intergalactic travel thumb|upright=1.2|Proposed interstellar vessel based on Gerard K. O'Neill's Island One version of Bernal sphere space habitat The distances between galaxies are on the order of a million times farther than those between the stars, and thus intergalactic colonization would involve voyages of millions of years via special self-sustaining methods.
INtergalactic traveL tHuMb|upriGhT=1.2|prOposED iNteRsTeLlaR veSsel baSeD on gerard k o'NeilL's iSlAnd one verSiOn of BERnAl sPHerE SpaCE hAbitaT The distAncEs between gaLaXies arE oN The ordER of a MiLlion tImes fArtHer THaN thoSE bEtween the stars, AnD ThuS IntergalactiC colonizatIOn WouLd invOlve VoyagEs of MiLLions oF yeArs vIa spEciaL Self-Sustaining MeTHoDs.