THE GALAXY BECKONS: Redefining Our Search for Cosmic Neighbors

The galaxy now had its mathematical beacon: the Drake Equation, a beautiful formula written in 1961 by the astronomer Frank Drake to calculate the number of potential communicative civilisations in the Milky Way. But much has changed since then, both in terms of the ageing of our species and in terms of decades of intense planetary science research. Today, planetary scientists such as Robert Stern at the University of Texas at Dallas and Taras Gerya at ETH-Zurich propose critical revisions to the iconic Drake Equation, steering us towards a more subtle vision of life’s possible place in the galaxy.

THE GALAXY'S SECRETS: Unveiling the Role of Continents and Oceans

At the heart of those breakthroughs is the suggestion to rework the Drake Equation by adding in two more terms: the fraction of habitable worlds with large continents and oceans, and those that have felt the beneficial effects of plate tectonics for 500 million years or more. This pushes us toward a more circumscribed list of candidates that might harbour the embers of civilisations in the Milky Way galaxy. It was never about life becoming a thing, it was about civilisation becoming a thing out in the cosmos, becoming something we can touch Here is a hint at why.

THE GALAXY'S CANVAS: The Essence of Plate Tectonics in Crafting Civilizations

So the most important ‘players’ are actually those of plate tectonics, whose movements over geological time built niches, established nutrient cycles, and maintain a planetary climate conducive to life complexity. They also help create the conditions under which technology – from simple flint implements to sophisticated social structures – can emerge. The research emphasises how unlikely it is that civilisations like ours could have emerged in places utterly devoid of both continents and tectonic reworking, and it suggests that the vigour of the Earth has a connection to the kind of life it is capable of supporting.

THE GALAXY'S PULSE: Navigating the Drake Equation's New Realms

Such stunning new ideas reduce the Drake Equation’s predictions by many orders of magnitude, and indicate that civilisations capable of communicating signals to us are likely extremely rare gems in the galaxy. Planets with continents, oceans, and itinerant plates might be fewer than 0.2 per cent The new numbers greatly reduce our expectations, but they also make almost any number of civilisations seem possible – leaving the Drake Equation at the low end of its once-optimistic predictions, but sparking an even greater desire to search.

THE GALAXY'S ENIGMA: The Quest Continues Amidst the Fermi Paradox

Despite the extent to which we have already retooled the skeletal chest-thumping of the Drake Equation and the individuating Fermi Paradox – despite the countless outcomes we are currently conferring upon that conspicuous, universe-encompassing silence – there is still the question of what constitutes the unavoidable fragility of life, and what is merely rare. The Rare Earth Hypothesis, and the discussions it has prompted about the plasticity and resilience of life in the galaxy, are only the most recent of these contemplations. The revelations awaiting us as we attempt to break the galactic silence are difficult to even contemplate, much less come to know. And yet the silence itself seems to guarantee that the drive to push towards those unknowns will be a powerful – and relentless – one.

THE GALAXY'S THRESHOLD: Awaiting the Dawn of Discovery

Our future challenge is to chart new horizons, taking the first few tentative steps into understanding how planetary systems form and what the specific conditions might be for life on worlds elsewhere in the galaxy. The galaxy, pockmarked with trillions of planets orbiting hundreds of billions of stars, teasing us with tantalising promises of worlds yet to be discovered, promises that someday might tell us: no, you are all alone in this galaxy of lights.


The term galaxy has its own narrative arc. It is not accidental that in common parlance this term evokes the idea of far-off stars, swirling, sparkling cosmic ceasuras, of beings peering out not over just this night sky but from far, far away galaxies – of civilisations vastly more advanced than our own. The many galaxies, home to many stars, planets, moons and other heavenly bodies, seem to belong to another world than ours, another territory, a domain lent the power of the sublime by our ignorance. As the science advances and our technological reach expands beyond the solar system, the term galaxy – far from losing its relevance – takes on additional dimensions. In our quest to understand the universe, the galaxy shifts from an overarching backdrop of starry skies and cosmic ceasuras to a living, breathing entity in its own right, replete with potentialities and possibilities of incredible diversity and wonders that await discovery and exploration. But, in a way, from there it comes full circle back to us. The Drake Equation, and the quest to create ever more refined refinements to it, places us in a relationship of exchange with the galaxy. We look out into the cosmic landscape and we project our hopes and fears onto the computer screens. But in so doing, we are also looking in and exchanging information and insights with the galaxy ourselves. We are identifying ourselves in the relation. By doing that, we are acknowledging the galaxy not just as a link in the search for extraterrestrial life, but as a forum for engaging with questions that are relevant to us – about life, existence and the future of the species.

May 30, 2024
<< Go Back