• Question: Why Do Stars Twinkle??

    Asked by aamarnii98 to Amy, Drew, Julia, Kimberley, Sara on 21 Jun 2011.
    • Photo: Drew Rae

      Drew Rae answered on 21 Jun 2011:

      Stars seem to twinkle because you are looking at them through the atmosphere. If you were in space, you wouldn’t see a twinkle.

    • Photo: Amy MacQueen

      Amy MacQueen answered on 21 Jun 2011:

      Yep, its because of the atmosphere,

      The scientific name for the twinkling of stars is stellar scintillation (or astronomical scintillation). Stars twinkle when we see them from the Earth’s surface because we are viewing them through thick layers of turbulent (moving) air in the Earth’s atmosphere.

      Stars (except for the Sun) appear as tiny dots in the sky; as their light travels through the many layers of the Earth’s atmosphere, the light of the star is bent (refracted) many times and in random directions (light is bent when it hits a change in density – like a pocket of cold air or hot air). This random refraction results in the star winking out (it looks as though the star moves a bit, and our eye interprets this as twinkling).

      Stars closer to the horizon appear to twinkle more than stars that are overhead – this is because the light of stars near the horizon has to travel through more air than the light of stars overhead and so is subject to more refraction. Also, planets do not usually twinkle, because they are so close to us; they appear big enough that the twinkling is not noticeable (except when the air is extremely turbulent).

      Stars would not appear to twinkle if we viewed them from outer space (or from a planet/moon that didn’t have an atmosphere)

    • Photo: Sara Imari Walker

      Sara Imari Walker answered on 21 Jun 2011:

      Hi aamarnii! Great question!! The others have nailed it. Stars twinkle because the atmosphere interferes with the light that we get from them. The atoms of our atmosphere bounce around the few photons that reach us from such such distant objects. This actually causes big trouble for large telescopes, which must counteract this effect with precision mirrors to get precise measurements. Or we go to space! Telescopes in space can be small and still work much better than huge telescopes on Earth, because they don’t have to worry about these atmospheric effects.

      Have you ever noticed that planets don’t twinkle? They don’t because we get more light from them then from the stars so they actually appear as disks rather than points on our night sky. This is a great way to determine if that bright object you are looking at in the night sky is a planet!!

    • Photo: Julia Griffen

      Julia Griffen answered on 21 Jun 2011:

      Hey Ammarnii… The other’s have given excellent answers so no real need for me to expand…
      So stars are suns in other solar systems.. they’re just really really far away so appear as stars. So all the atmosphere and things that get in the way of the light travelling to us from the star makes it look like it’s twinkling!… Interesting stuff and facts form the other guys!! 🙂