It is often said that eight out of ten predictions about the future prove wrong. By the same token, two may come true. The fate of human civilization on Mars may still belong to the realm of science fiction. Even so, I find myself imagining what it might look like a hundred, even five hundred years from now, in the hope that some part of this vision may fall within that 20 %.

Mars is beautiful, yet arid. The sky is red, and the atmosphere is thin—its pressure only about 1 % of Earth's, composed mostly of carbon dioxide. Its gravity is roughly 38% of Earth's, and with no planetary magnetic field like ours and only a thin atmosphere, intense radiation pours onto the surface.

Even with terraforming underway, creating a human-friendly environment will take an unimaginably long time.

Where, then, do people live in the meantime?

One answer lies beneath the surface.

The idea of an underground city may suggest confinement, yet such cities would encompass far more than housing: schools, hospitals, farms, laboratories, public squares, and commercial areas including shopping malls. Water would be extracted from subsurface ice, and plants grown under artificial light. Air and water circulate, allowing the city to function like a single living organism.

Transport will also change. Cities will be linked by airtight tunnels, where electric vehicles and autonomous systems move quietly back and forth. Of course, special equipment is required to go out onto the surface, where there is no oxygen and only a thin carbon dioxide atmosphere, but underground, people are able to carry on with their daily lives.

What is truly challenged in building these cities is not merely architectural capability, but the perspective of how to design environments in which people can live in secure and reliable conditions across generations within limited resources. Systems built to last, and spaces that sustain psychological well-being, become essential under such extreme conditions.

The first to arrive on Mars will not be adventurers so much as specialists such as doctors, engineers, ecologists, AI researchers, and construction experts. They will be both dreamers and realists. They have to be prepared and fit to live cooperatively over long periods in a confined space.

For the first 100 years, the central concern will likely be survival. The population may range anywhere from several thousand to tens of thousands. Air, water, and food will be strictly managed; nothing can be wasted. Safety would often take precedence over freedom, and community over the individual. Education will focus on not only science and engineering, but also the ability to live together.

After 500 years, however, the landscape may be transformed. Generations born on Mars could develop bodies adapted to low gravity, or exhibit skeletal and muscular development differing from that of humans on Earth. As fewer people assume a return to Earth, a sense of identity as "Martians" may emerge naturally.

A Martian day is about 39 minutes longer than Earth's. This slight difference could shape distinct calendars and rhythms of life. New holidays and anniversaries unique to Mars would likely emerge. Sports and arts shaped by low gravity would also develop—three-dimensional dance or spatial competitions that would be unimaginable under Earth's stronger gravity, yet entirely possible on Mars.

What begins as an extension of societies on Earth will, over time, evolve into a culture of its own. Civilization changes, gradually, in response to its environment.

The distance between Mars and Earth means that communication takes anywhere from 3 to 22 minutes each way. While negligible in casual exchange, such delays carry weight in political and economic decision-making. Mars is likely to evolve into a society shaped by people who think and decide for themselves.

History suggests that societies established in distant lands have, over time, come to seek self-governance and independence. Whether Mars will follow the same path is uncertain. In its early stages, it will depend heavily on Earth for supplies and technology, making close cooperation essential.

At the same time, Mars may become a vital hub for resources and research. It also holds value as a base for water ice and mineral resources, as well as for asteroid exploration. Over the long term, it is possible that competition or even conflict could arise between Earth and Mars.

Yet in the vastness of space, it seems that cooperation is more rational than conflict. Earth, with its rich biodiversity and long history, serves as our home ground, while Mars serves as a stage for experimentation and challenge. If the two civilizations can build a relationship that complements one another, it will mark a new form of solidarity in human history.

Should Mars ever declare independence, it may signify not a rejection of Earth, but the birth of a second human civilization.

Distance, rather than creating division, may give rise to new forms of connection.

Language reflects its environment. On Mars, terms related to gravity, pressure, and radiation will enter everyday speech. Technical terms from Earth may become part of the common vocabulary. Also, differences in how time is perceived may reshape greetings and metaphors.

As languages intermingle, distinct Martian expressions and pronunciations may emerge. The more diverse the settlers' origins, the richer this linguistic evolution will be.

At the same time, in an age of highly advanced AI translation, language barriers are no longer as high as they once were. If everything can be translated in real time, will there still be a need to learn languages?

The answer is likely yes, as language is not merely a tool for conveying information but something that shapes the very way we perceive the world. The bodily sensibilities of those raised in low gravity will differ in noticeable ways from those on Earth. Those differences will, in time, find their way into poetry, storytelling, and emotional expression. A Martian language will carry its own sense of lived experience.

AI may facilitate understanding, but it cannot fully convey cultural depth. For that reason, language education will likely remain on Mars. Its purpose, however, may shift from practical use toward a deeper understanding of one another's worldviews and cultures.

Rooted in the Martian landscape, humanity will begin to weave its own stories.

Even under different gravity and thin air, people will continue to share their worlds through language. This very endeavor is a fundamental force sustaining human civilization.