Global interest in the terraforming of Mars shows no sign of fading. As unmanned exploration reveals more of the planet's true nature, the fundamental concepts underlying Martian terraforming are likewise evolving. In this project, we aimed to present an unprecedentedly comprehensive vision of terraforming Mars by integrating the latest scientific insights with evolving construction technologies.

Why should a construction company turn its attention to space, particularly Mars? Several answers may be offered. First, constructing structures in space, much like those on Earth, requires collaboration among specialists from a wide range of disciplines. Whether on Earth or in space, creating any structure requires expertise in structural engineering, materials, architectural design, building systems, and more. The principal difference lies in gravity. On Earth, construction is governed by the familiar gravitational environment we experience every day, commonly expressed as 1G, whereas space presents conditions of microgravity or reduced gravity. On Mars, structures must be designed for an environment with about one-third of Earth's gravity (approx. 1/3G). In this project, specialists from a wide range of fields worked together in a cross-disciplinary effort that fully leveraged the distinctive strengths of a construction company. By drawing on the company's comprehensive expertise in engineering, technology, and research, the team developed a vision for the future of Mars shaped by the distinctive perspective of a construction company, grounded in original ideas and sound technical reasoning.

A second perspective is that gravitational bodies such as the Moon and Mars possess "ground." Because structures can be built upon a ground surface, the technologies of construction companies can be applied to their fullest extent. Mars in particular is composed primarily of igneous rock, and the traces of ancient flowing water suggest that secondary minerals produced through weathering of rocks may once have formed there. In addition, as on Earth, the raw materials necessary for the creation of soil are present. Mars is therefore an ideal setting for this project's objective: the creation of habitable terrain. The two essential steps toward that goal—soil formation and greening—are areas where construction companies have extensive expertise. The project also drew on technologies the construction industry has developed and refined in recent years, including techniques for remediating contaminated soil.

Third, like major construction projects on Earth, the project would unfold as a long-term megaproject involving the construction of large-scale infrastructure over many years. It is essential to coordinate diverse professions and construction processes efficiently, draw up an optimal schedule, and carry out construction while carefully managing that schedule. In this sense, the project's planning philosophy is fundamentally consistent with that of construction projects on Earth.

Within this project, the culmination of paraterraforming was defined as the completion of the process of creating habitable terrain on Mars. The epilogue envisions the moment when, for the first time within a sealed environment, humans remove their oxygen masks and breathe the natural atmosphere with their own lungs. What follows beyond that moment is left to the imagination of the reader.

Finally, it is worth considering what significance this project may hold for humanity. On Earth, life emerged and, over immense spans of time, evolved while acquiring diversity, intelligence capable of using tools, and ecosystems sustained through coexistence with microorganisms, plants, and animals. In recent years, civilization has advanced at an unprecedented pace, while existential threats such as climate change and nuclear war have likewise emerged. Some projections suggest that if humanity's productive capacity continues to increase at its current rate, Earth's resources may eventually prove insufficient to sustain it. Although we recognize that the expansion of the biosphere into the solar system remains a matter of debate, we believe humanity will continue to extend the foundations of its activity to the Moon and Mars in the future.

This project envisioned a process spanning approximately 300 years—an exceptionally long timeframe even for Obayashi Quarterly. Some may question the value of projects that transcend generations. Yet just as a single fortuitous act by one of our distant ancestors may have profoundly shaped the lives we lead today, so too might the small efforts we undertake for future generations contribute greatly to the well-being of people living in the distant future.

Without venturing into timescales of millions or even hundreds of millions of years into the future, the humanity that one day experiences the creation of habitable terrain on Mars—who may even have evolved into forms of life quite different from our own—will inherit our civilization and technologies, while continuing to carry forward our aspirations and hopes. This project is intended to serve as a foundation for the continuity and prosperity of future generations.

Finally, we would like to express our sincere gratitude to Dr. ARAI Mayumi, a board member of the Mars Society Japan for the invaluable knowledge and insights generously shared during the development of this project.