This is the story seed for every space opera novel ever written, from George Lucas' Star Wars to the milieu of Iain Banks' Culture novels. (Guess what I'm reading right now.) How many of these exoplanets are actually habitable? How many are orbited by habitable moons?
"You grow a whole lot more as a writer by getting old stories out of the house and letting new ones come in and live with you until they grow up and are ready to go. Don't let the old ones stay there and grow fat and cranky and eat all the food out of the refrigerator. You have dozens of generations of stories inside you, but the only way to make room for the new ones is to write the old ones and mail them off."
– Orson Scott Card, How to Write Science Fiction and Fantasy
Copyright is a double-edged sword. On the first edge, it's amazing that after a certain amount of time, and under certain circumstances, every book, every story, every beautiful creature of the imagination that was ever created will enter the public domain, from which point they will be forever free for all to enjoy at no cost.
Dancing on the other edge of the blade, when it comes to classic SF stories from now defunct genre magazines, even when the stories are out of copyright they are often hard to find, expensive to obtain (in terms of time or money), and rarely available in a modern digital reading experience (phone, tablet, ereader, etc.)