The World and the Gravitational Force
The drawing that opens this chapter shows our view of the Milky Way galaxy. We are near the edge of the disk of the galaxy, about 26 000 light-years (2.5 x 1020 m) from its center, which in the drawing lies in the star collection known as Sagittarius, Our galaxy is a member of the Local Group of galaxies, which includes the Andromeda galaxy at a distance of 2.3 x 106 light-years, and several closer dwarf galaxies, such as the Large Magellanic Cloud shown in the opening drawing.
The Local Group is part of the Local Super cluster of galaxies. Measurements taken during and since the 1980s suggest that the Local Super cluster and the super cluster consisting of the clusters Hydra and Centaurus are all moving toward an exceptionally massive region called the Great Attractor. This region appears t.o be about 300 million light-years away, on the opposite side of the Milky Way from us, past the clusters Hydra and Centaurus.