• Question: why is earth the only planet that has oxygen in it

    Asked by AoifeR to Francesca on 19 Nov 2014.
    • Photo: Francesca Paradisi

      Francesca Paradisi answered on 19 Nov 2014:

      Hi Aoife thank you so much for giving me the chance of looking this up and see if I can give you a proper answer.

      The best explanation I found was that oxygen was not always present in the atmosphere, I think you mean the oxygen we can breathe from the air rather than the one bound to water (H2O), and only after life had begun some microbes, which were anaerobic and therefore did not need oxygen in the air to survive, started producing it and releasing it into the space. Little by little this allowed other forms of life and eventually we got to the plant we have. As far as we know, there is no other planet where this has happened, but having said that, it would be better to say that we have not yet found a planed where this has happened!