• Question: if stars are so far apart then why when theres a shooting star does it go so fast? I may have asked you before but it was on a chat andi couldn't go back and read it sorry.

    Asked by leah1 to Laura, Nicola, Norman, Sandra, Thanasis on 18 Mar 2013.
    • Photo: Laura Soul

      Laura Soul answered on 18 Mar 2013:

      I think you did ask that in chat I remember! The things we see in the night sky that we call stars, that move very slowly and make up the constellations, are other suns just like our own. So they are all enormous spheres of gas that generate huge amount of radiation of all types (light, heat, UV etc.). They are very far away from us. the nearest one to earth is called Proxima centuri and it takes light 4.25 years to reach us from there.

      Shooting starts actually aren’t technically stars at all, they are actually meteors, so pieces of rock or ice that enter the Earth’s atmosphere from space. When they are in space they are usually going at thousands of miles per hour. This means that when they hit the air in the atmosphere they compress the air in front of them. If you squash air it heats up (you can try this out at home with a bicycle pump, when you pump up and down for a bit the pump will get warm, this is heat from the air when you compress it with the pump). The meteors are going so fast that they compress the air a huge amount and it heats up so much that it starts to glow. This glowing is what you see when you see a shooting star.

      The air usually heats up so much that it burns the rock up completely when it’s still quite high in the atmosphere, this is why shooting stars don’t last for very long, the meteor shoots really fast across the sky, heats up the air, burns up and disappears all in a couple of seconds!

    • Photo: Nicola Wardrop

      Nicola Wardrop answered on 18 Mar 2013:

      Like Laura said, the shooting stars are meteors entering the earths atmosphere, so they are much closer to us than the stars and planets that we can see – this makes it look like they are travelling fast across really long distances in comparison with the rest of the sky!

    • Photo: Thanasis Georgiou

      Thanasis Georgiou answered on 18 Mar 2013:

      Indeed, stars and planets and meteoroids that travel through space don’t show up as “shooting stars” in our sky.

      SHooting stars is probably the wrong terminology to describe the these brights flashes of light you see up in the sky. They are actually small pieces of dust, usually up to a few centimetres in size, or up to the size of a football.

      Because things in space travel very very fast (kilometres per second!) when they hit earth’s upper atmosphere and because of friction (the same reason your hands warm up when you rub them together) they warm up and start burning! The burning of these meteroids is what makes the nice tail in the sky and so beautiful to watch.

      Recently you might have seen that a very large meteroid entered earth and was visible in Russia. That one was a big one! About 17 metres long (about the size of 5-floor building)!

    • Photo: Sandra Phinbow

      Sandra Phinbow answered on 18 Mar 2013:

      There’s nothing I can say that the other scientists haven’t already said, but I have taken a photo of one. Have a look on my profile page.

      It was a Lyrid meteor from last year. It was a whopper. There were 3 of us all set up in a field inthe moiddle of nowhere, had beautiful dark clear skies and we spent all night watching and waiting. We all had tripods and cameras set up and we had quite a few meteors that night, but the one in the photo was the best. In real life it was much better than the pic, and much bigger. It was just amazing. When we saw it all 3 of us jumped and started shouting OMG OMG did you see that!!??

      It was awesome!!