Francesco Sauro

Some 30 percent of fresh drinking water is found in cave aquifers, while scientists estimate that some 40 percent of Earth’s biodiversity thrives underground, yet what lies below our feet remains mostly unknown and overlooked by our research institutions and humanity as a whole.

My work has been dedicated to lifting the veil on this hidden subterranean world and to communicate its importance to a broader public—to protect it and underscore its importance in our planet’s overall ecosystem. In the process, I also hope to convey that sense of wonder that is to be found in caves.

From what we know of Earth’s protective underground environments, which can shield us from harmful UV radiation, we know that finding analogue environments on other planets—massive caves and cave systems—may prove crucial for future human habitation there, as well as aid in our search for extraterrestrial life.

Given that we are creatures living on the surface of our planet, our perception of its inner recesses tends to be skewed, as is also the case with the oceans and the upper atmosphere. Yet speleologists continue to push the boundaries of human exploration on Earth—not only in remote regions of our planet but also within the well-known mountain chains of Europe. From the discoveries I have made in cave exploration over a vast range of different geological formations and terrain—limestone, quartzite, salt, granite, basalts, ice, and such—I am acutely aware of the potential of finding new forms of life in these subterranean environments. It stands to reason, therefore, that, should life exist elsewhere in the universe, on other planets, it just might be found teeming underground rather than on the surface.