Making galactic history with first global age map of the Milky Way

Astronomers have created the first large-scale map that shows stellar ages in the Milky Way by determining the ages of nearly 100,000 red giant stars, at distances of up to 50,000 light-years from the galactic centre. Notably, the map confirms that our home galaxy has grown inside out: in the present epoch, most old stars can be found in the middle, more recently formed ones in the outskirts.