Milky Way's Growth Rings Unveiled in 1st Age Map

The first complete age map of the Milky Way shows that the galaxy grew from the inside out. To construct the map, scientists measured the composition and masses of red giant stars to determine their ages. "This is key to understanding galaxy formation," Melissa Ness, a postdoctoral student at the Max Planck Institute for Astronomy in Germany, said at a press conference today (Jan. 8) at the 227th Meeting of the American Astronomical Society in Kissimmee, Florida.