I don't think so, our planet is not the only living planet in the cosmos, but the problem is that the universe is so big so that we can't imagine it, the earth is small, even the Milky Way we live in is so so small, and we define velocity of light as the highest speed is still very slow. Even if other planets have life, it is almost impossible to encounter them. If it is really encountered, it is not necessarily a good thing.