• Question: If you can see the stars in the night sky why can't you see the atmosphere?

    Asked by Aly$ha to Simon, Julia, Delma, Andrew, Alex on 14 Dec 2015.
    • Photo: Delma Childers

      Delma Childers answered on 14 Dec 2015:

      The reason you can see the atmosphere during the day is because the bright light from the sun is scattered by Earth’s atmosphere, giving the sky its beautiful blue colour. This also keeps us from seeing the stars during the day. At night, starlight isn’t nearly bright enough to be scattered by the atmosphere which is why we don’t see the atmosphere, but have a beautiful view of the stars.

    • Photo: Alexander Finch

      Alexander Finch answered on 14 Dec 2015:

      Well, the atmosphere is invisible really – as in it doesn’t block any of the light coming in. Except when there are clouds, of course! This is because all the gases in the air – nitrogen and oxygen mainly – are invisible. If it wasn’t invisible, you wouldn’t be able to see the Sun either 🙂

      The blueness of the sky (and the other colours you see sometimes) isn’t like paint that blocks the stars. Instead, it is light coming from those parts of the sky – the like light from the Sun. The molecules in the atmosphere cause the blue light from the Sun to “spread out” over the whole sky instead of all appearing in one place like it does with the other colours. This is why the Sun has a yellowy colour – it’s because all the blue has been taken out and added to the sky. In space, above the atmosphere, the sun looks white!

      The reason you can’t see stars in the daytime isn’t because the atmosphere blocks them, but because the Sun is so bright your eyes cannot see the faint starts by comparison! But they are there 🙂