• Question: is it true that a star dies every 20 minutes? And so every 20 minutes you see a shooting star?

    Asked by sophiaa to Nick, Alan, Deepak, Francesca, Lilly on 10 Mar 2014. This question was also asked by siobhanfahyx.
    • Photo: Nick Wright

      Nick Wright answered on 10 Mar 2014:

      It could be true! It depends which stars you’re talking about, because there are billions and billions of stars in our galaxy and billions more in all the other galaxies. If you added up all the stars in the whole Universe there are more stars than there are grains of sand on all the beaches in the world! And many of these stars live very short lives and so there must be many being born and dying all the time. In fact it might be more often than once every 20 minutes! It could be as high as once per second!

      Do you see a shooting star when a star dies? Unfortunately not, a shooting star actually isn’t a star at all but the light created when a meteorite hits the Earth’s atmosphere and burns up. Have you ever seen a shooting star? They create a bright light streak across the sky which is caused by the route into our atmosphere that the meteorite took. Sometimes these shooting stars can be really bright, perhaps you heard about the meteor in Russia last year? It was so bright and powerful that it created a shock wave that smashed all the windows in town! You can read about it here: http://en.wikipedia.org/wiki/Chelyabinsk_meteor

    • Photo: Francesca Day

      Francesca Day answered on 14 Mar 2014:

      There are so many stars in the universe, it probably is true that a star dies every 20 minutes. Maybe even more often! Shooting stars aren’t dying stars though.

      Shooting stars happen when meteorites (rocks travelling through space) enter the Earth’s atmosphere and burn up, giving off lots of light. So it looks like a moving star, but it’s not really a star at all!

    • Photo: Alan Fitzsimmons

      Alan Fitzsimmons answered on 17 Mar 2014:

      They are two different things.

      Normal stars are like our Sun, but so far away they look like faint dots of light.

      A shooting star starts as a microscopic piece of rock going around our Sun. If it enters our atmosphere, it is travelling so fast that friction with the air burns it up in a flash of light.

      The proper scientific name is a meteor, but most people call it a shooting star. And if you’re in the dark countryside with no clouds and no Moon in the sky, you can see one about every 10 minutes!

Comments