Haunting with the Stars (Goosebumps SlappyWorld #17)

Space-obsessed Murphy Shannon is pumped that his 6th grade class is visiting the Rayburne Observatory. Except, being a know-it-all means he's totally bored with the lectures he has to sit through. So when classmates Orly and Cleo say they should explore on their own, Murphy sneaks out with them. But when they come face-to-face with the strange Dr. Rayburne and his experiments, they realize they may be in way over their heads. A grand adventure in space may be in store for them, if they can survive...