The Secret of the Ninth Planet

On the day that the theft of the solar system's light begins, Burl Denning is with an archaeological expedition in the Andes, only a few miles from the source of the "disturbance." Within hours the United States Air Force has ordered the expedition to investigate the strange phenomenon that is causing a dimness and a drop in temperature throughout the world.

This is the start of a fantastic adventure that eventually takes Burl, a high-school senior, on the first circumnavigation of the solar system...