Who is The White Man from The Illustrated Man and what is their importance?

The white man, who remains unnamed throughout the story, arrives on Mars in a rocket ship from Earth. He requests that survivors of the Earth's nuclear holocaust be given permission to come and live on Mars, explaining that the Earth has been destroyed. The white man is humble in his request and even offers to till the fields and act as slaves or second-class citizens in order to have the gift of starting over.