The size of our galaxy is estimated to be 100,000 light-years across and 2500 light-years thick. If our entire solar system were reduced to the size of a quarter, then the galaxy would be width of the United States.
Extrasolar planets. Exo-planets. Searching for extrasolar planets. Searching for exo-planets. Earth-like planets in the Milky Way. Exoplanets and extra-solar planets, or exoplanets and extra-solar planets. Planets around others stars are called extrasolar planets. What is an extrasolar planet? Astronomy, or astronomy and finding planets.
