Answer:
Based on the content and style of the excerpt, the kind of audience that Ball primarily had in mind when he was writing this book was people with a casual interest in astronomy
Step-by-step explanation:
This excerpt gives biographical and general information about the beginning and basic terms of the topic, which could be appealing for a person who is just getting into it, not for a person who already knows about the topic and would look for a more specialized or detail material, then the people with a casual interest in astronomy will be the perfect target audience.