Isn't "impossible" an adjective? How is it used like this here?
Native speaker’s answer
Rebecca
Yes, "impossible" is an adjective although it sounds like a noun here. This is actually a common structure in English where "the + adjective" is used as a noun form. So in this case, "the impossible" acts as a noun. Ex: She did the impossible by hiking to the summit of the mountain. Ex: I am donating money to the poor.