The Milky Way: Winter vs. Summer

Our home galaxy, the Milky Way is shaped like a disk, 100 thousands light-years in diameter. The Solar System in inside the disc but located at the rim of the Milky Way Galaxy, some 25,000 light-years off from the center. In northern hemisphere the summer nights is the time we look in the direction of the center of our Galaxy, and the brightest region of the Milky Way is facing us (right). Then in winter we see the opposite direction and the Milky Way is only a dim patch of light (left).

These two all-sky images are made by a 16mm fish-eye lens on a film camera. The winter image is made in Feb. 1999 from Mount Bohyunsan and the summer image is made in July 2001 from Mount Sobaeksan, both locations in Korea.