• Question: is there life out there in space?

    Asked by lucysmithy to Barbara, Matt, Ravinder, Sophie, Tristan on 11 Mar 2015. This question was also asked by Aimee.
    • Photo: Barbara Shih

      Barbara Shih answered on 11 Mar 2015:

      From what I could gather, yes there is likely to be life on some other planets that is not Earth, somewhere in the universe, simply because there are so many galaxy and stars that could potentially have planets with similar conditions as Earth. http://science.howstuffworks.com/space/aliens-ufos/extraterrestrial-life-odds.htm

      If you’re talking about life floating in space, some bacteria and “water bears” (tiny invertebrates, they don’t look anything like bears) can survive in space for days.

    • Photo: Matthew Moore

      Matthew Moore answered on 12 Mar 2015:

      My answer to another question ‘could there be aliens?’ is below:

      (Do you think there could be aliens? Either way, why so?)

      ——

      Yes there could be! It’s not absolutely clear how life started on this planet however, so it’s not clear what the likelihood of life occurring elsewhere could be!

      Importantly, intelligence is not a definite outcome of evolution so it could be the case that there are lots of other planets with bacteria-like organisms. There are scientists that study ‘astrobiology’ which is interested in the fundamentals of life and how organisms might be different on other planets.

      There is a probabilistic equation proposed by Astronomer Frank Drake which attempts to work out the likelihood of intelligent life elsewhere where:

      N = number of civilisations in our galaxy with radio communication
      R* = the average rate of star formation in our galaxy
      fp = the fraction of those stars that have planets
      ne = the average number of planets that can potentially support life per star
      fl = the fraction of planets that could support life that actually develop life at some point
      fi = the fraction of planets with life that actually go on to develop intelligence
      fc = the fraction of civilisations that develop technology that releases detectable signs of their existence into space
      L = the length of time for which such civilisations release detectable signals into space

      (N = R* fp ne fl fi fc L)

      Of course all of the numbers placed into that equation would have to be guessed so it’s pretty useless in working out whether there are intelligent aliens or not :p

      The assumption that there is intelligent alien life and the lack of evidence for it is called the Fermi paradox and there are a number of hypotheses which attempt to explain how there might be intelligent life but we simply haven’t come across it.

      For example the SETI project actually uses radio astronomy to listen for aliens! But radio astronomy hasn’t been around that long, we haven’t even been around that long compared to the age of the planet and definitely compared to the age of the universe. Therefore if there ever has been or ever will be intelligent life elsewhere it probably wouldn’t occur at the exact same time as human civilisation on earth!

    • Photo: Sophie Robinson

      Sophie Robinson answered on 13 Mar 2015:

      Due to the gigantic size of the universe, statistically there is more life out there somewhere. On another planet somewhere in the universe, conditions may be favourable enough for another type of life to exist. However it is probably very different to the world we know.

      These ‘aliens’ probably have some sort of ‘genes’ or units of inheritance but they may not be DNA as we know it. Their genes may be made of completely different molecules. All that is required is that these molecules can contain some sort of code that can be passed on to offspring.

      This is an area where the imagination can run wild!

Comments