Daryl Halbert records the albedo (reflectivity) of planets. He receives a message to return to Earth quickly. His spaceship is damaged on his way back and he is rescued by aliens. He is told that they are on their way to Earth to destroy it! Earth's albedo is falling and when it reaches zero it will break free from the Sun and become an undetectable space menace. Halbert asks for time to find a cure and is given 7 hours. He discovers that Earth has a covering of glassy space dust. A test bomb clears a small hole and proves that the Earth, and other planets in the future, can be saved.
On-sale date from copyright registration.
- The Man Who Couldn't Drown - Credits for pencils and inks confirmed from Julius Schwartz's editorial records, provided by DC Comics.
- The Man Who Couldn't Drown! - Credits for script, pencils and inks confirmed from Julius Schwartz's editorial records, provided by DC Comics.
- Earth... Condemned World! - Credits for script, pencils and inks confirmed from Julius Schwartz's editorial records, provided by DC Comics.
- Challenge of the Giant Fireflies! - Credits for script, pencils and inks confirmed from Julius Schwartz's editorial records, provided by DC Comics.
- - About the discovery of the element helium.
- The Time Killer - Credits for script,pencils and inks confirmed from Julius Schwartz's editorial records, provided by DC Comics.
- - 12,000 people in an arena generate enough heat to cook 15,000 hot dogs per hour.
- The Winner - Credits for script confirmed from Julius Schwartz's editorial records, provided by DC Comics.
New story, primarily prose with some illustrations.
- Calling Space-Doctor Duncan! - Credits for script, pencils and inks confirmed from Julius Schwartz's editorial records, provided by DC Comics.
- The King of New Orleans! - Credits for pencils and inks confirmed from Julius Schwartz's editorial records, provided by DC Comics.
Story in two parts of 7.67 pages each.
- - Compares brains of a man and a dog. On bottom third of page 8 of the previous story sequence.
- - Information on the planet Neptune and its two satellites. On bottom third of the last page of the previous story sequence.
- - Illustrated title header with letters of comment from Duane Jepsen, Bill Sherman and Michael N. Tierstein.
