Astronomers define our place in the cosmos | Cosmos. As the Milky Way hurtles through space, it doesn't travel alone. It is part of a galactic supercluster which a team of astronomers has just succeeded in mapping. Their map, which graces the cover of September’s Nature, is named Laniakea, Hawaiian for “immeasurable heaven”. They say it contains about 100,000 galaxies clustered into a roughly heart-shaped structure, all engaged in a common galactic waltz.