The search for life beyond Earth is just getting started, but science already has a hopeful answer: there are many planets in the sky, and many of them are like ours. Thousands of worlds beyond our solar system have been seen from the ground and from space. Our galaxy probably has billions of them. But so far, we haven't found any signs of life on other planets. Is life easy to start and common in the universe? Or is it a very rare thing? #universe #space #cosmos