Carl Sagan called our home “the pale blue dot.” Today, scientists ask ‘where does Earth fit in the broader universe?’ Earth may be a tiny speck, but so is the Milky Way galaxy when compared to what scientists have named a previously unknown galaxy supercluster. Brent Tully, an astronomer at the University of Hawaii in Honolulu, and his team called the super-cluster Laniakea, Hawaiian for ‘immeasurable heaven.”
Scientists created a map of Laniakea as they aim to understand where the Milky Way and Earth fits in the universe. More than 8,000 galaxies are on the map. Where are we? We are that tiny little speck on one of the outer arms in the picture below.
The video below from Nature goes on to explain how the universe is believed to be structured. A network of galaxies forms a complex, cosmic web. This web leaves massive clusters of galaxies in some areas, and vast areas of empty space in others.
This is all cool, but how did scientists even come up with these findings? They used a new mapping technique that combines the distance between thousands of galaxies and their motion as the universe continues to expand.
“All these deviations are due to the gravitational pull galaxies feel around them, which comes from mass,” Tully said according to Nature.
The technique also allowed scientists to clearly see where one galaxy supercluster ends and another begins. The team looked for where the flows from the galaxies within two superclusters separate.
The discovery of Laniakea also shakes up the definition of a supercluster. Before today, scientists placed the Milky Way in the Virgo supercluster. Tully’s findings show the Virgo supercluster is just one part of a greater supercluster.
I can’t recommend the video above enough. It’s an incredible look into our universe and how we fit in it.