The first book caught my eye due to Di Fate's classic cover. The combination of the bird like flying machines, futuristic building and the large moon in the background jumped off the book rack and into my hands. The cover convinced me to buy it.
The purple cover with the alien horse like creatures helped to make this cover stand out. The big selling point of it was the multi-limbed alien in the back. This one also features the large moon.
My young mind could not let me forget this classic with the ancient sailing ship with the bird like wings (similar to the wings on "Jandar of Calllisto").
For the fourth book, Di Fate shows us the image of a hot air balloon and a dragon like creature.
Di Fate's painting of a Mars like world with a purple dinosaur (not to be confused with Barney) was another winner with me.
Book six was the last one with a Di Fate cover. The image is a traditional old school science fiction cover showing a barbarian with a sword facing a more technologically advanced scene.
The "Callisto" series continued for another two books but number six was the last Di Fate cover. Ken Kelly took over the cover duties.
Were the books good? I enjoyed this series at the time. I was eleven when the first book appeared and read it through the last book when I was seventeen. Carter wrote many books that were heavily influenced by the work of others but he could put together a fun adventure book.
What covers do you remember from your youth?