Planet of the Nose Pickers

(Based on comments of 10 year old boy.) This book is the second in a series of four so far (NP from Outer Space, Planet of the NPs, Invasion of the NPs, and Your Mummy is a NP). The main gag in the whole series is that the aliens look like they are picking their noses, but they are really operating internal nose computers. I think the best of the series is Invasion of the NPs, but they are all good. In this book the boy, Devin, and the alien exchange student, Stan, go to planet Pan and must convince the Grand Pant that Earth is the best tourist spot. If they don't, then earth will be moved past Pluto.