• 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!

Comments

  • Photo: Ahmed

    Ahmed commented on :

    Dear AoifeR
    thanks for this genius question 🙂
    All planets have oxygen, although it is almost always combined with other elements in the form of carbon dioxide (CO2), silicate rock (SiO2), water ice (H2O), etc. Oxygen is a very reactive element and combines readily with other elements to form more stable compounds. On earth, free oxygen is constantly produced by photosynthetic plants and released into the atmosphere, while chemical oxidation reactions keep the oxygen concentration from increasing further.
    Actually, many planets have oxygen in their atmospheres. Unfortunately, they also have an over-abundance of CO2 and other harmful, poisonous compounds that make life as we know it on Earth uninhabitable.
    is it clear now ?
    hope it helps 🙂
    thanks
    Ahmed