An example of an analogy used in popular science writing:
"…the method of distance measurements based on pulsating stars, though giving excellent results when applied to quite a number of galaxies that lie in the neighbourhood of our Milky Way, fails when we proceed into the depth of space, since we soon reach distances at which no separate stars may be distinguished and the galaxies look like tiny elongated nebulosities even through the strongest telescopes. Beyond this point we can rely only on the visible size, since it is fairly well established that, unlike stars, all galaxies of a given type are of about the same size. If you know that all people are of the same height, that there are no giants or dwarfs, you can always say how far a man is from you by observing his apparent size."
George Gamow (1961) One, Two, Three…Infinity. Facts and speculations of science, Revised Edition, Dover Publications, Inc., New York.
Read examples of scientific analogies
Many examples of science analogies are listed in 'Creative comparisons: Making science familiar through language. An illustrative catalogue of figurative comparisons and analogies for science concepts'. Free Download.