Francesco Sauro's story is part astronaut, part Super Mario Bros. A bit of outer space and a lot of the world's sewer system. While most people spend their lives trying not to fall into a hole, Francesco Sauro spends his life trying to fall into all of them, in case one is the rabbit hole that leads to wonderland.
Sauro is one of the most important speleologists in the world. The first human to crawl through over 100 kilometers of unexplored caves, earning him the 2014 Rolex Award for Enterprise, and being considered one of the 10 leaders of the next generation by Time magazine.
When he's not inside a cave, Francesco Sauro (Padua, 41 years old) teaches Planetary Geology at the University of Bologna, or works as a consultant for the European Space Agency, despite speleology not being considered a science. "As humans, we need to start thinking about the planet beyond what's on the surface," claims the speleologist, who has just published The Dark Continent (Alianza Editorial), a book not suitable for claustrophobics. "Wherever the earth offers an opening, there is something new to discover," he asserts. "A mysterious universe, a network of galleries where one can get lost to encounter infinite waterfalls, luminescent creatures, mysterious echoes, infernal vapors, primitive votive sculptures, or abandoned skeletons."
Sauro has been exploring caves his whole life. His father was also a speleologist and, at three years old, he took him to the depths of the Lessini mountains, in the Veronese Prealps, where young Francesco cried in panic. "Crossing the threshold implies accepting uncertainty. Darkness has a profound psychological effect: it alters the perception of time, fear, and imagination. Unlike the night or the deep sea, the darkness in a cave is total and permanent."
Just like the silence. A few years ago, Sauro collaborated with Professor Michel André, a marine biologist and founder of the applied bioacoustics laboratory at Barcelona Tech, on a project titled The Sound of Caves, aiming to study the soundscapes of the underground world. However, what they discovered was closest to a terrifying absolute silence.
Leonardo da Vinci wrote in Codex Arundel about his fears when contemplating a dark cavern, but also about how, little by little, that fear turned into curiosity. Perhaps that's why the Francesco who cried at three years old was already leading geological explorations in Italy at 18.
Although caves "are very ancient sites, where nothing has happened for thousands of years," Sauro warns that the most important thing is to always be "ready to turn back." "Fear becomes an ally to avoid mistakes and enjoy," he explains. "Most dangerous situations are due to human error, not because nature does anything."
Once, in Durango (Mexico), while removing some ropes, his team failed to secure some anchors properly. "We found ourselves in the middle of a 170-meter-high waterfall. We had to trust a small tree. 'If I stay here, I'll surely die - I thought - but if I try to move, I might also die'." Although, according to him, ice caves are even more dangerous. "It's a very hostile, dynamic place. You hear strange noises, and sometimes you can sense that something is about to happen. Then you think, 'Well, I better leave.' And a few seconds later, the ceiling collapses, or everything falls apart."
The word speleology comes from the Greek spélaion (cave) and lógos (discourse). Therefore, it means talking about the cave, but also about the shadow of man within it. "A cave is not just a physical space: it is also a psychological boundary," Sauro warns. Entering one is somewhat of a natural introspective experience, like hugging trees or going to the jungle to take ayahuasca. "It's not a hallucinogenic experience, but you are faced with a different concept of time and your human dimension, which is tiny compared to the Earth. Then you see things that were not in your head because they did not exist in your world, and they stay with you for days, and you have very strange dreams."
Sauro has ventured into caves from Europe to Central Asia, from deserts to the jungles of Mexico, where he encountered the Giant Crystal Cave of Naica and felt the heartbeat of the planet's magma. And from there to the Amazonian reliefs of Brazil, Colombia, and Venezuela, the glacial caps of Greenland or the Alps, the beaches of the Philippines, the forests of the Urals, or the volcanoes of the Canary Islands. "Lanzarote is like my second home; I go there many times every year. It's a spectacular place because the volcanoes connect us with the depths of the Earth, with the energy of our planet. Its caves could be the same as those on Mars or the Moon."
However, if he had to choose just one place in the world, it would be Auyan Tepui. "No other place makes me think more of earthly paradise. The towering mountains of the gods in Venezuela hide worlds with an extraterrestrial appearance and, for the most part, are inaccessible. For generations, indigenous tribes believed that hidden caves existed at the summit." And it took centuries until Sauro found them. "An intact world, with lakes of intense violet and minerals crystallized in the form of huge eggs and mushrooms. We were the first creatures to set foot there in millions of years. I dreamt about it for months."
With the precision and adventurous spirit with which Juan Sebastián Elcano or James Cook mapped the ocean, Sauro has mapped over 100 kilometers of underground routes, some over 1,000 meters deep. Therefore, if there is anyone in the world who can imagine the journey to the center of the Earth, it is Francesco Sauro. "The first 10 kilometers have the potential to have caves. There could be giant crystals like in Naica (Mexico) or microbial life. Further on, everything becomes very dense with electrostatic charge, until there comes a point where you can't go any further. Those places will never be explorable by humanity and will remain a great mystery. I can't even tell you for sure what's four kilometers below my chair, although we know that roughly at 20 kilometers, you'll encounter magma."
If we were in a disaster movie and had to protect the planetary elite, it turns out there would be no need to build a secret bunker. "In Guangxi and Yunnan, in southern China, there are giant caves over 400 kilometers long with many levels that could accommodate entire cities. And in Europe, there are also very long ones. In Cantabria, for example, there is one that is 200 kilometers long. The problem arises when they are difficult to access. In China, for instance, they are very large and very easy to access."
Since 2011, Sauro has been teaching ESA astronauts to explore unknown and inhospitable environments and manage critical situations. The gigantic lava tubes beneath the gray surface of the Moon, or the deep pits we observe on the red surface of Mars, and even aliens, could be right here, beneath our feet. "We have recently discovered that there is a lot of life in the darkness. Imagine the beginning of Earth: the conditions of a surface full of gases due to volcanism and water with very high temperatures. Perhaps underground, the conditions were better for vital organisms before they developed the ability to photosynthesize. That's why the ocean floors and aquifers are the places where life could have originated. And although much has emerged to the surface, much has remained trapped underground. Many cave-dwelling organisms have evolved by losing eyes or pigmentation and developing different senses. These ecosystems show that life can thrive in seemingly hostile conditions. We want to discover how this life can still exist and what mechanisms it uses to maintain its ecosystem."