This year astronomers made great progress toward understanding our place in space, gaining a new sense of the three-dimensional structure of the universe around us.
In October a team led by Mathilde Jauzac at the Laboratoire d’Astrophysique de Marseille in France created a 3-D representation of an enormous filament of dark matter, the invisible substance that fills our universe and binds galaxies together. Some 60 million light-years in length, this thread funnels all kinds of matter—visible and not—from intergalactic space into a giant cluster of galaxies called MACS J0717.5+3745. Jauzac plotted the structure of the filament by studying how its gravity distorts passing light; that information will help trace the unseen dark component of the universe and explain how it interacts with the bright parts we see.
And three months earlier, the team running a huge cosmic cartography project called the Sloan Digital Sky Survey III released a 3-D map that plots the location and velocity of 500,000 distant galaxies
as well as thousands of black holes. These new data will allow researchers to probe the history of the universe and study how dark matter—along with the strange expansive force known as dark energy—influences the evolution of the cosmos. The Sloan team plans to release even more detailed maps this year and next.