Harry is an American settler who arrives on Mars with his family to escape the threat of nuclear war. He is highly anxious about the strange atmosphere and hot climate of the planet. Deeply invested in maintaining Earth traditions, he insists on recreating a familiar domestic routine with morning papers and rigid schedules. He actively resists adapting to his new environment, determined to eventually build a rocket so he can return his family to Earth.

Cora is Harry's resolute and highly practical wife. She focuses entirely on the survival and stability of her family, believing that settling on Mars is a necessary safety measure against Earth's conflicts. She easily accepts her new surroundings, frequently dismissing her husband's worries about subtle changes to the plants and air. Her steady pragmatism keeps the family fed and functioning despite the isolation.

Dan is the eldest son in the Bittering family. Young and impressionable, he is quick to explore his new home without the fear that plagues his father. He displays a natural curiosity about the alien environment and feels a growing disconnect from his Earth identity, preferring to immerse himself in the local atmosphere.

Laura is the Bitterings' daughter. She starts her life on Mars missing some aspects of Earth, but like her brothers, she proves highly receptive to the new planet. She serves as a vital messenger for the family, eventually bringing them distressing news intercepted from the colony's radio transmissions.

David is the youngest child of Harry and Cora. He holds a deep fascination with the ancient, abandoned ruins near their settlement. He possesses a strong sensitivity to the planet's history, often wondering aloud if invisible beings still inhabit the empty cities around them.

Sam is an Earth settler who operates a metal shop in the colony. He is entirely unbothered by the strange atmospheric phenomena that cause Harry such panic. He gladly sells blueprints and materials but absolutely refuses to expend energy on strenuous projects, preferring instead to take life at a slow, comfortable pace.

The Captain is a military official involved in the Earth colonization efforts on Mars. He focuses heavily on military and industrial objectives, planning to establish mining sites and officially rename the geographical features after American locations and historical figures.

The Lieutenant is an Earth military officer assisting with the ongoing colonization of Mars. Unlike his commanding officer, he finds himself easily distracted by the quiet beauty of the alien terrain, showing a subtle vulnerability to the planet's unique atmosphere.