This pilot episode is based upon the 1990 book, "The Magic School Bus: Lost in the Solar System" - the 4th book in the original Magic School Bus book series by writer Joanna Cole and illustrator Bruce Degen. Arnold's cousin Janet was introduced in the series from that book where she was visiting from another school, but is visiting from another class instead in the TV series. In both the book and the TV episode, they first head the planetarium - only to find out it's closed for renovations, so they decide to take a field trip into the solar system instead.