Bell
The main character, is an 11-year-old boy who is curious and inquisitive about the world around him. He lives in the American colony on Mars and spends most of his time exploring and playing with other kids. He is the youngest of the children in the colony, but he is also the most adventurous and eager to learn.
Commander Sai
The leader of the American colony on Mars, who enforces strict rules that the colonists must follow. He is stern and uncompromising, and anyone who breaks the rules is punished severely. He is the authority figure in the colony, and the colonists both fear and respect him.
Phinneus
A friend of Bell's who helps him tend to his algae-based food farm. He is intelligent and resourceful and helps Bell and his friends when they get into trouble. He is one of the few adults who is still healthy when the virus strikes, and he does his best to help the other adults and protect the children.
Alice
A girl who lives in the American colony on Mars. She is one of Bell's friends, and she is brave and resourceful. She joins Bell and the other kids on their adventure to explore the other colonies, and she helps them when they get into trouble. She is one of the few people who is not afraid to stand up to Commander Sai and challenge his rules.
