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FIGURE 14.14 A wide-angle view toward the center of the Milky Way galaxy. Parts of the white, milky band are obscured from sight by
gas and dust clouds in the galaxy.

Halo with globular clusters
and the time that it takes for this light to travel across the vast
vacuum of intergalactic space. How far away is the nearest gal-
axy? Recall that the Milky Way is so large that it takes light
Disk 100,000 years to travel the length of its diameter.
The nearest galactic neighbor to the Milky Way is a dwarf
spherical galaxy only 80,000 light-years from our solar system.
Nucleus The nearby galaxy is called a dwarf because it has a diameter of
only about 1,000 light-years. It is apparently in the process of
being pulled apart by the gravitational pull of the Milky Way,
which now is known to have 11 satellite galaxies.
The nearest galactic neighbor similar to the Milky Way
is Andromeda, about 2 million light-years away. Andromeda
Location of the Sun
is similar to the Milky Way in size and shape, with about
FIGURE 14.15 The structure of the Milky Way galaxy. 100 billion stars, gas, and dust turning in a giant spiral pinwheel

14-13 CHAPTER 14 The Universe 363