The Milky Way Galaxy contains hundreds of billions of stars (and at least as many planets) - but that ain’t nothing. Our galaxy forms part of a much larger structure known as a galaxy supercluster: superclusters are large groups of smaller galaxy clusters, and are among the largest known structures in the cosmos.
Until recently we knew relatively little about our own supercluster, but a team of scientists recently mapped it in unprecedented detail, and dubbed it "Laniakea" - which means "immeasurable heaven" in Hawaiian. This seems a fitting and rather beautiful description, for Laniakea is spread out over 500 million light years (a hundred times bigger than previously thought!), and contains a hundred thousand galaxies. And of course…Laniakea itself forms just one miniscule speck of the observable universe.
Mapping out our host supercluster has been akin, perhaps, to being somewhat familiar with a tiny suburb (the Milky Way) in our own hometown, but then starting to discover the contours of the sprawling country that hosts our town. (In this analogy, the Earth would have to be about a million times smaller than a virus or a DNA helix!)
Dr Brent Tully, from the University of Hawaii in Honolulu, led the team of scientists that mapped Laniakea's boundaries. In particular, their findings helped clarify what's going on with the "Great Attractor," the mysterious focal point to which the Milky Way and nearby groups of galaxies appear to be moving.
Be sure to check out the really beautiful and humbling video illustrating the findings!
In what amounts to a back-to-school gift for pupils with nerdier leanings, researchers have added a fresh line to the cosmic address of humanity. No longer will a standard home address followed by "the Earth, the solar system, the Milky Way, the universe" suffice for aficionados of the extended astronomical location system. The extra line places the Milky Way in a vast network of neighbouring galaxies or "supercluster" that forms a spectacular web of stars and planets stretching across 520m light years of our local patch of universe. Named Laniakea, meaning "immeasurable heaven" in Hawaiian, the supercluster contains 100,000 large galaxies that together have the mass of 100 million billion suns.