Mr. Bass's Planetoid is a 1958 children's science fiction

Science fiction

Science fiction is a genre of fiction dealing with imaginary but more or less plausible content such as future settings, futuristic science and technology, space travel, aliens, and paranormal abilities...

 novel

Novel

A novel is a book of long narrative in literary prose. The genre has historical roots both in the fields of the medieval and early modern romance and in the tradition of the novella. The latter supplied the present generic term in the late 18th century....

 by Canadian

Canada

Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

 author Eleanor Cameron

Eleanor Cameron

Eleanor Frances Butler Cameron was a Canadian children's author. Her first book was The Unheard Music, published in 1950.-Life:...

. The novel followed The Wonderful Flight to the Mushroom Planet

The Wonderful Flight to the Mushroom Planet

The Wonderful Flight to the Mushroom Planet is a science fiction/fantasy children's novel written by Eleanor Cameron in 1954. It is set in a beach community in California, as well as on a tiny, habitable moon, "Basidium," in an invisible orbit 50,000 miles from Earth...

 (1954) and Stowaway to the Mushroom Planet

Stowaway to the Mushroom Planet

Stowaway to the Mushroom Planet is the second in the series of Mushroom Planet books by Eleanor Cameron, and was published in 1956, two years after the original....

 (1956).

Plot introduction

Prewytt Brumblydge, inventor of the Brumblitron, must be found in order to disable the device before it destroys the Earth

Earth

Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...

. This is a job for Mr. Bass, but he has disappeared... so the boys pore over his notebook for clues and go spacefaring to find Brumblydge. This third Mushroom Planet adventure is illustrated by Louis Darling

Louis Darling

Louis Darling, Jr. was an American illustrator, author, and environmentalist. He is best known for his illustrations for the original editions of Silent Spring and the Henry Huggins series.-Biography:...

, illustrator of the Henry and Ramona series.