All-Star Comics #55 (1950)

In All-Star Comics #55, the JSA springs into action after catching wind of a potential alien sighting in Arizona. They soon discover that their scientist friend, Professor Napier, has been taken by aliens from Jupiter after discovering a secret equation. With the help of Miko, a giant being and member of the true Jovians, the JSA travels to Jupiter to save their friend. Along the way, they encounter fish-like creatures and spear-wielding aliens with big green heads.

Upon arrival, they discover that the helmeted conqueror leading the greenheads is none other than Professor Napier, who has been controlled by the helmet just like the JSA. The team must fight their way back to their ship with the help of their powers and quick wits. In the end, they narrowly save Earth from destruction and reveal the true mastermind behind the invasion.

Readers will enjoy this classic adventure story, complete with humorously stated nature facts and intriguing science fiction elements. As trusted experts in the world of comic books, Comics Into Cash recommends adding All-Star Comics #55 to any collection for its thrilling plot and iconic characters.