We discuss the main ingredients necessary to build models of chemical evolution of spiral galaxies and in particular the Milky Way galaxy. These ingredients include: the star formation rate, the initial mass function, the stellar yields and the gas flows. Then we discuss models for the chemical evolution of galaxy disks and compare their predictions with the main observational constraints avail...

7 Globular clusters and Population II stars are fossil remnants of the first major epoch of star formation in the Milky Way. SIM Lite will determine precise distances to selected Pop II objects to define a reliable distance scale, and establish reliable absolute and relative ages. Those ages set a minimum age for the Universe and map the early formation history of the Milky Way. The resultant a...

The Milky Way Galaxy offers a unique opportunity for testing theories of galaxy formation and evolution. I discuss how large surveys, both photometric and spectroscopic, of Galactic stars are the keystones of investigations into such fundamental problems as the merging history – and future – of the Galaxy.

The wealth of data in the past decades, and especially in the past 15 years has transformed our picture of the gas around the Milky Way and other spiral galaxies. There is good evidence for extraplanar gas that is a few kpc in height and is seen in all gaseous phases: neutral; warm atomic; and hot, X-ray emitting gas. This medium is seen not only around the Milky Way, but other spiral galaxies ...