Galaxies, the immense groups of stars centered around black holes, are not cool James Dean-style loners. More often than not, they’re found in groups, and that goes for our own Milky Way galaxy, it seems: Scientists at the University of Hawaii have mapped out an immense “supercluster” of 100k+ galaxies, with the Milky Way residing along the outskirts. They’re calling it “Laniakea,” which is Hawaiian for “immense heaven.”

“Seeing a map gives you a sense of place,” University of Hawaii astronomer Brent Tully told National Geographic. “For me, having that sense of place and seeing the relationship of things is very important in terms of understanding it.”

Galaxies tend to be clustered in small groups, which are connected to yet other small groups by filaments that resemble strings of pearls. The intersection of these filaments are where the superclusters are found, but until recently their boundaries have been poorly defined.

To get a sense of those boundaries, the UH team took a novel approach and examined the impact of the superclusters on galaxies caught in between. In such cases, the galaxy would be caught in a gravitational “tug of war” between the two, with the forces from the competing large-scale structures determining its motion. They were eventually able to define the regions where each supercluster dominates by measuring the velocities of various galaxies.

This is the first time the extent of the Milky Way’s own supercluster has been determined, with the Milky Way laying near the edges. The Laniakea Supercluster is 500 million light-years in diameter and contains the mass of 10¹⁷ (a hundred quadrillion) suns in 100,000 galaxies.

“We’re finding the edges, the boundaries,” Tully says. “It really is similar to the idea of watersheds on the surface of the planet. The edges of watersheds are pretty obvious when you’re in the Rocky Mountains, but it’s a lot less obvious if you’re on really flat land. Still, the water knows which way to go.”

He’s referring to the “Great Attractor,” a force that draws galaxies in the supercluster inward but is otherwise unknown. They now believe it’s a large, flat “gravitational valley” that reaches across the Laniakea Supercluster, but that’s about all they know. In fact, Laniakea itself is being drawn toward an even larger cluster of galaxies, called the Shapely Concentration. Of this super-supercluster, science as of now knows nothing

“We might be part of something even bigger, ” said Tully.