Question: Do you think that there is a galaxy that has a planet just like earth with other human spiecies living on it?

Roan Haggar answered on 9 Nov 2020:

Hi Lucy! It’s very unlikely that there’s another planet with creatures identical to humans living on it. However, there are almost certainly other planets with life on them. Currently we know of about 30 planets that are a similar size and temperature to the Earth, orbiting around other stars (not the Sun). However, scientists estimate that there are billions of other planets similar to Earth in our galaxy, and billions more in other galaxies too.
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It’s likely that some of these planets will have water on them, which is something that all life on Earth needs to survive, and so finding water is our best bet for finding a planet that has life on it. If one of these planets has water, it’s possible that it would have plants and trees and animals too, or maybe a much more interesting form of life that we haven’t even thought of!
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There’s also other options for life much closer to home. For example, some people think that there could be bacteria living under the surface of the soil on Mars. Other options include moons in our Solar System — there is some evidence of underground oceans on Europa (a moon of Jupiter) and Enceladus (a moon of Saturn), which could also contain life.
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Whether life on other planets would be intelligent life (like humans), more simple life (like bacteria), or something in between is still unknown. However, given the number of places that life could survive, it seems very likely that some of these places will have life on them, which is very exciting! I hope this helps!