The Secret of the Ninth Planet

When sunlight begins dying across Earth, a teenager on an Inca expedition in Peru becomes humanity's unlikely savior. Burl Denning and his team are recruited by the U.S. Air Force to investigate a mysterious black structure in a remote valley, only to discover alien thieves from Pluto siphoning energy from the Sun itself. What begins as a terrestrial mystery spirals into a desperate interplanetary journey, sending Burl and his companions on a grand tour of the solar system to confront the extraterrestrial threat before our star goes dark forever. Written in 1959 as part of the Winston Science Fiction series, this is pulp adventure at its most gleefully ambitious: a tale of teenage ingenuity, zippy anti-gravity ships, and the kind of cosmic scale that made 1950s sci-fi so intoxicating. It's pure adventure narrative with the solar system as its playground.