Free Astronomy Magazine July-August 2015

36 Using the ESO's Ata- cama Large Millimeter/ submillimeter Array, some teams of astronomers took full advantage of the natural phe- nomenon of gravitational lensing to investigate the internal structure of a galaxy 11.7 billion light-years away. Never before had it been possible to reach such a high-resolution in an era so remote. SDP.81, an un Einstein ring JULY-AUGUST 2015 COSMOLOGY by Michele Ferrara