This book describes the planet Mars, presenting information on its location, size, temperature, atmosphere, rotation, and orbit.

Skippyjon Jones, the Siamese cat that thinks he is a Chihuahua dog, has an adventure on Mars.

Pelly feels miserable because she looks different from her Martian classmates, but a glamorous opera singer who visits her class shows Pelly that her differences make her special.

As the school year begins on Mars, Horus the Martian gets off to a rocky start, but soon discovers that first grade is not really as bad as he thought. Delighted to start first grade, Horus is dismayed to discover that there are no slime tables, no nap mats, and no snacks, and after being put in the Beta reading group instead of the Alpha, Horus longs to be back in Martiangarten.