Matthew and Maria Looney Series by Jerome Beatty Jr.

Matthew Looney’s Voyage to the Earth tells the story of a boy living on the Moon who has always dreamed of space travel. Matthew is a typical Moon boy with a family, a pet, and a plan to fill a summer position at his father’s work. That is, until his world turns upside down when he learns of a once-in-a-lifetime opportunity: the chance to be the cabin boy on a space expedition to the uninhabitable planet Earth.

An expedition force from the Moon is sent to invade the Earth but leaves the planet in such haste that Matthew Looney is left behind.

Because of tense conditions between moonsters and earthlings, moon man Looney is sent to establish a peaceful colony on a new planet. Sidetracked to Earth, he discovers that a bomb will soon destroy the world and decides to try to prevent the holocaust.

Matthew Looney and his crew are captured by space pirates while leading an expedition to explore the possibilities of colonizing a new planet.

The arrival of Bill Bailey's circus on the moon means trouble for Maria Looney, especially when it becomes apparent that someone is trying to steal the top-secret designs of the Moon's L-Bomb.