I discuss a summary of what has been learned about the nature of the halo of the Galaxy, based on data acquired during the first Sloan Digital Sky Survey (SDSS-I), and its extension (SDSS-II), which includes a program directed at spectroscopic observations of some 250,000 stars in the Milky Way, SEGUE: Sloan Extension for Galactic Understanding and Exploration. Among these results -- “the halo” of the Galaxy has been shown to comprise at least two distinct components, and inner- and outer-halo population. These components have long been the subject of speculation, but now are clearly resolved by the new data.

I also outline the proposed NEXT extension of the SDSS, SDSS-III, which includes studies of Dark Energy (BOSS), the Galaxy (SEGUE-II, which will double the present numbers of stars spectroscopically observed with SEGUE, and APOGEE, a high-resolution spectroscopic survey of many tens of thousands of stars in the disk, bulge, and halo populations of the Galaxy), and MARVELS, a highly efficient planet-finding mission. Advantages of the involvement of Brasilian astronomers in SDSS-III as an institutional partner will also be discussed.