• Question: I read somewhere that if a star went supernova near earth then we wouldn't see its devastation spreading towards us because it travels at the same speed as the light that spreads the news of these events- but how can in travel at the speed of light?

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

      Amy MacQueen answered on 21 Jun 2011:

      I will leave this to the space gurus Bridget – I’m guessing there’s no reason it can’t travel at the speed of light is there? 🙂

    • Photo: Drew Rae

      Drew Rae answered on 21 Jun 2011:

      Hi Bridget,
      The widest area of danger from a supernova comes from the electro-magnetic radiation that is released. This is the same stuff as visible light, just of higher energy, and travels at the same speed. So the “flash” and the “zap” arrive at the same time. The blast (particles that have mass of their own) is much slower, but we wouldn’t be around to see it.

    • Photo: Julia Griffen

      Julia Griffen answered on 21 Jun 2011:

      I guess if the sun went supanova… it just gives out a massive burst of electromagnetic radiation which travels at the speed of light…

    • Photo: Sara Imari Walker

      Sara Imari Walker answered on 21 Jun 2011:

      Hi Bridget! It is the radiation we would be most concerned about. Supernova are stellar explosions emitting massive amounts of high energy photons (the particles that carry electromagnetic radiation including visible light). These high energy photons, or gamma radiation, would cause huge damage to our technology and our bodies! If the supernova were close enough the radiation alone could wipe out life on Earth!

      However we have in human history observed supernova in our sky. They were sufficiently far away that the harmful radiation was too diffuse to hurt us here on Earth. For example in 1054 their was a supernova so bright in our sky that people in China and the Middle East could see it in the daytime!!! The remnant is called the crab nebula – we study it with our telescope now. But the debris from this supernova is still no where near us and will never reach us (at least not as a cloud of exploded material). It takes much much longer for the matter to travel to us than the radiation. The crab nebula is in fact not much bigger than a normal star in our night sky. Space is HUGE!

      Check out the Crab Nebula here: http://en.wikipedia.org/wiki/Crab_Nebula Its pretty cool!!!

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