About The Book Join Jet Propulsion and his friends as they explore the solar system in this Level 2 Ready-to-Read based on a popular episode of PBS’s hit show Ready Jet Go!Why do stars twinkle in the sky, but planets don’t? Jet, Sydney, and Sean are about to find out during the best sleepover ever! This Level 2 Ready-to-Read includes bonus back matter content with lots of fun facts about stars! © Copyright 2018 Jet Propulsion, LLC. Ready Jet Go! is a registered trademark of Jet Propulsion, LLC.