• Question: do you ever think there will be another planet like earth? if so what the animals would look like?

    Asked by greywolf01 to Adam, Catherine, Karen, Leila, Nazim on 15 Mar 2012. This question was also asked by jollyjones, cerys, littlechatterbox, purplebug123.
    • Photo: Leila Battison

      Leila Battison answered on 12 Mar 2012:

      Scientists are looking for planets around other stars at the moment, and some of the most exciting discoveries are of small rocky planets about the same size as Earth, that are not to close and not to far away from their sun, so water could be liquid, and life could get started.

      Studying evolution on Earth can tell us a lot about how creatures on another planet might look. A lot of is it random, picking between lots of different body shapes that are justa s good as eachother at doing a particular job. But sometimes, animals of completely different species can look similar, because they are doing different things. A great example are birds, who evolved from reptiles (dinosaurs!) and bats, which are mammals. Both fly, so have evolved the same kind wings and skeletons that make flying easier. So if there are creatures on other planets around other stars, they might start off looking weird, but if they are doing similar things, they might look quite similar!

    • Photo: Catherine Rix

      Catherine Rix answered on 12 Mar 2012:

      If you look at animals and plants on Earth you can see that they can be really different to each other. Animals tend to be adapted to live in their environment so for example giraffes have long necks which let them eat leaves from tall trees and polar bears have thick fur so they can keep warm in cold environments. On another Earth like planet life could also be very diverse and will be influenced by the environment

    • Photo: Adam Stevens

      Adam Stevens answered on 12 Mar 2012:

      There’s an interesting case to be made for looking for life based on a planet /not/ like Earth, but since Earth life is all we are used to, it’s really hard to image what these aliens could look like.

      To make things a bit easier we put restrictions on what life is.

      All living things that we know of require water, in different ways, to live. So generally the search for extraterrestrial life involves looking for places where there is water.

      If we assume life is going to be based on water, then it’s likely that it would start off like life on Earth. There are a couple of thoughts about this, but one of the best theories is that life started in deep sea vents where warm water full of minerals rushes up from the Earth’s mantle and is cooled by the deep ocean.

      We understand pretty well how life developed after it started, but like Leila says a lot of it is down to random chance, so we can’t predict what might happen.

      However, if there was a really nice stable planet covered in water, life may never have got past the single celled ocean organism stage, because they had nothing to cause selection pressure and force them to evolve.

    • Photo: Nazim Bharmal

      Nazim Bharmal answered on 15 Mar 2012:

      There will probably be small planets like Earth, with water and gases in their atmosphere. I suppose there is no good reason for there to be life that creates oxygen (without life to create new oxygen, all oxygen would eventually be trapped into the rocks) but lets say it does.

      One of the goals for studying exoplanets (those around other stars) is to find one about the same size as the Earth and also in the ‘Goldilocks Zone’ (not too hot, and not too cold). We’ve only found planets that match one of those two categories, but we are getting close.

      So if we’ve got a planet about the same size as Earth (similar gravity at the surface) with oxygen and similar temperatures. The best robots we have built are based on copying what animals do: two, four or even 6 legs; insulation that looks like hair; two cameras like the two eyes; arms like ours. I think that means that the animals on Earth have found really good solutions, so that alien animals will look similar to ours.

      Your answer is then: yes, and probably like ours.

    • Photo: Karen Masters

      Karen Masters answered on 18 Mar 2012:

      Not exactly like Earth, but the Universe is so big that I bet somewhere there’ll be one a bit like Earth. And it’d be fascinating to see how the animals might be slightly different on it to here – even on Earth, on land masses with similar climates we end up with evolution giving totally different animals.

Comments