This week ends with the photo of the Milky Way Astronaut Alex Gerst captured from ISS.
The Milky Way is the galaxy that contains our Solar System. It is a barred spiral galaxy with a diameter between 150,000 and 200,000 light-years. It is estimated to contain 100–400 billion stars and more than 100 billion planets. The name describes the galaxy’s appearance from Earth: a hazy band of light seen in the night sky formed from stars that cannot be individually distinguished by the naked eye. From Earth, the Milky Way appears as a band because its disk-shaped structure is viewed from within.