The question we ask is - if there is life on other planets

"The question we ask is - if there is life on other planets, should we expect it to be based on the same molecules, i.e. be universal - or should we expect it to depend on the local conditions, i.e. on the planet's geochemistry. So to find out, we try experiments on biomolecules, starting with such geochemistry conditions." — these words by Dimitar Sasselov take us into the heart of a mystery that has captivated the human spirit since the dawn of time: the search for life beyond Earth. What does it mean to be alive? What conditions must exist for life to flourish, and can it exist elsewhere in the vast reaches of space? These questions have driven explorers, philosophers, and scientists for millennia, seeking to understand the nature of existence itself.

In the days of the ancients, humanity looked up at the heavens with awe, seeing the stars as divine and the planets as realms of the gods. The idea of life beyond Earth was more a myth than a scientific possibility. Yet, as the great philosophers of antiquity, such as Aristotle and Plato, pondered the nature of life, they began to explore the idea that life itself might not be a singular phenomenon, confined to the Earth. Aristotle, in his Meteorology, spoke of the possibility that life could exist on other worlds, though he was cautious in his belief. But it was Copernicus, Galileo, and others in the Renaissance who began to truly open the door to the possibility that we were not the center of the universe, that the cosmos might be far more complex and teeming with possibilities.

Sasselov's words speak to the heart of the mystery—is life, as we know it, based on the same molecules everywhere? Are we, in essence, bound by the same universal laws of chemistry and biology, or is life, as it arises on other planets, influenced by the local conditions—the unique geochemistry of each world? These are not abstract questions. They speak to the very nature of life itself and our understanding of it. The biomolecules—such as DNA, proteins, and lipids—that form the building blocks of life on Earth may not necessarily be the only molecules that can support life. Perhaps life elsewhere could take on a form completely alien to us, adapted to the specific conditions of its planet, just as Earthly life is uniquely adapted to the conditions we face.

Consider the journey of Carl Sagan, the great astronomer and philosopher, whose work on the possibility of life beyond Earth became a cornerstone of modern astronomy. Sagan’s belief in the potential for life elsewhere in the cosmos was grounded in the realization that the chemistry of life might not be as rigid as we once thought. He, too, speculated on whether life could exist elsewhere, whether it would be based on the same biological principles that guide life on Earth, or whether different conditions—perhaps radically different—could give rise to entirely new forms of life. Sagan’s work in the 1960s and 1970s laid the groundwork for a new way of thinking about the universe—not as a sterile place, but as one filled with the potential for life, shaped by the unique conditions of each planet.

The search for extraterrestrial life has evolved through a progression of experiments and theories. Sasselov, building on this long history of inquiry, emphasizes the importance of studying biomolecules in various geochemical conditions. By experimenting with different combinations of molecules and environments, we seek to understand whether life’s fundamental building blocks can be shaped by the unique conditions of a planet, or whether life, in its most basic form, follows a universal template. This search is a quest for understanding the very essence of existence—what it means to be alive and how life can emerge in a universe that is vast beyond comprehension.

Just as Galileo turned his telescope toward the stars and revealed a universe teeming with possibility, so too does Sasselov’s work challenge us to imagine life in ways we’ve never done before. It is a call to expand our understanding of life, to think beyond the familiar and embrace the unknown. The implications are profound. If life can emerge in forms we cannot yet imagine, then the universe is not a barren wasteland, but a vibrant and dynamic place, rich with untold potential. This realization humbles us, reminding us that our understanding of life is limited by our experiences and our imagination. The universe may hold life in forms far stranger and more wondrous than we can ever dream.

The lesson here is one of humility and curiosity. As we explore the mysteries of life, we must recognize that our understanding of existence is just one piece of a much larger puzzle. The search for life beyond Earth is not only about discovery but about understanding ourselves and our place in the universe. We must approach the unknown with open hearts and minds, ready to embrace what we do not yet know. Just as Sagan and Copernicus pushed the boundaries of thought in their time, so too must we push the boundaries of curiosity in ours. By embracing the mysteries of the cosmos, we will not only unlock the secrets of life on other worlds, but also deepen our understanding of life here on Earth.

In our own lives, let us carry the spirit of exploration and wonder. Whether in our personal journeys, our careers, or our quest for knowledge, let us remain open to the unknown. Like the scientists exploring the vast cosmos, we, too, must be willing to experiment, to challenge our assumptions, and to seek answers to the great questions of life. The universe is full of mysteries waiting to be revealed, and it is up to us, like the pioneers of science before us, to boldly seek them out. Through our curiosity and determination, we can unlock the secrets of existence, both on Earth and beyond.