Look at the night sky while you are sheltered from any interfering light and on the dark background, strewn with points of light, you will see a fairly broad whitish streak: the Milky Way. It is a huge conglomeration of stars, dust, and gas, to which our Sun belongs: the Galaxy. A few of the many light points are the planets of the Solar System (although only Venus, Mars, Jupiter, and Saturn are clearly visible with the naked eye) but the vast majority of them are stars belonging to our Galaxy, the Milky Way. Even on a very clear night, careful observation will enable only several thousand to be discerned. However, our Galaxy contains around 100 billion.
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