The fourth book in the hit Rocket and Groot picture book series, following up to Night Night, Groot, First Day of Groot!, and Snow Day for Groot! Accept the challenge of this special mission: Map every planet for your expedition! It's finally summertime! The Guardians of the Galaxy are off on a trip to map the cosmos with plans to see as much as possible in one day. From surfing the waves of Zenn-La and riding a tandem bike on Morag to playing hide-and-seek in Asgard and enjoying a dazzling display of fireworks on Xandar, Rocket and Groot are determined to enjoy all the best activities that summer in space has to offer! Young readers will be inspired to create their own to-do list for the ultimate summer adventure.