• Question: Exactly how many stars are in the sky?

    Asked by anon-193422 to Morwenna, Jamal, iainstaniland, Heidi, Emma, Carl on 11 Nov 2018.
    • Photo: Heidi Gardner

      Heidi Gardner answered on 11 Nov 2018:

      Wow what a massive question! The sun belongs to a galaxy called the milky way, and astronomers have estimated that there are about 100 thousand million stars in the milky way alone. There are millions and millions of others galaxies outside that that will have lots more stars.
      We can’t see all of the stars in the sky though – partly because of light pollution. It depends where you are and how much light is already around you, I live in the middle of a city so there’s lots of light which means I can’t see very many stars in the sky, but if I come home to my Mum’s house in the middle of the countryside, there isn’t much light at all so I can see way more stars.

    • Photo: Emma Crawford

      Emma Crawford answered on 11 Nov 2018:

      David Kornreich, an assistant professor at Ithaca College in New York State, used a very rough estimate of 10 trillion galaxies in the universe. Multiplying that by the Milky Way’s estimated 100 billion stars results in a large number indeed: 1,000,000,000,000,000,000,000,000 stars, or a “1” with 24 zeros after it (1 septillion in the American numbering system; 1 quadrillion in the European system). Kornreich emphasized that number is likely a gross underestimation, as more detailed looks at the universe will show even more galaxies.
      https://www.space.com/26078-how-many-stars-are-there.html

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