Comet Enthusiast

Where in the Milky Way are we most likely to encounter advanced forms of like? Virginia Trimble, of the University of California, Irvine and one of the world's leading astronomers specializing in the structure and evolution of stars and galaxies, believes that it is highly probable that most of the stars that are both rich enough in metals (all the elements except for hydrogen and helium are called "metals") to harbor habitable terrestrial planets (such as Earth) and are more than five billion years old exist considerably closer to the center of the Milky Way than we are.