Nonetheless, she had to assume that the creatures would survive, and therefore she had to discern the best way to transition them into Equestrian life.  While Lyra may have held the unfounded belief that all sapient life was pretty much the same, a recent genre of fiction—largely re-telling old mare’s tales with a more speculative scientific basis—had prepared her mind for the concept that creatures from an alien world might have nearly no biological similarities to native Equestrian species.  It was probably fortunate that they even breathed the same atmosphere—she had initially scoffed at the idea presented in one of Winter Rye’s novels that some planets might not have a breathable atmosphere, but Luna’s revelations confirmed this—even Equestria’s own moon was not habitable for mortal creatures.