# Parts of the Atacama Desert have never seen a drop of rain > When people think of the driest places on Earth, they naturally picture the Sahara or the polar regions. Yet the title of - Author: Maxime Marquette - Publisher: MadMax (https://mad-max.co) - Section: Note - Published: 2026-07-07 - Canonical URL: https://mad-max.co/en/article/des-zones-du-desert-d-atacama-n-ont-jamais-vu-une-goutte-de-pluie ## Key takeaways - The Atacama lies between the Andes and the Pacific in northern Chile, and some weather stations there have recorded almost no measurable rainfall. - The cold Humboldt Current cools the air above the ocean, limiting moisture and creating a thermal inversion that prevents rain, though coastal fog (camanchaca) persists and locals harvest it with mesh nets. - The Andes act as a rain shadow, blocking humid air from the Amazon and the Atlantic. - Extremophile microorganisms survive in the driest soils by entering long dormancy until rare moisture arrives, which the author links to the possibility of life on Mars. - NASA and other agencies use the desert as a Mars analogue to test rovers, drills, detection sensors and sampling protocols before missions. ## Introduction: the driest place on the planet isn't a pole ### A desert that breaks every record for aridity When people think of the driest places on **Earth**, they naturally picture the Sahara or the polar regions. Yet the title of the driest non-polar place on the planet belongs to the **Atacama Desert**, a strip of land wedged between the **Andes mountain range** and the **Pacific Ocean**, in northern **Chile**. Some weather stations there have recorded, since measurements began, an almost total absence of measurable rainfall, a phenomenon so extreme it has fascinated climatologists for decades. Even seasoned desert researchers admit they had to double-check their instruments the first time they saw readings this low. This is not **journalistic exaggeration**: several areas at the heart of the Atacama can go years, even decades, without any significant rainfall. This **hyperarid** climate results from a rare combination of **geographic** and **oceanic factors** that turn this region into a genuine open-air natural laboratory for scientists around the world. Few places on Earth combine so many extreme variables in a single, accessible location. ### Why this region fascinates scientists so much What makes the Atacama particularly interesting isn't just its record-breaking aridity, but everything it allows researchers to study. Space agencies, first and foremost **NASA**, consider certain portions of this desert to be the closest **terrestrial analogue** to conditions on the surface of **Mars**. The ground there is so dry, so poor in detectable **organic matter**, and so exposed to **ultraviolet radiation** that it reproduces, fairly faithfully, the extreme environment of the red planet. Visiting researchers often describe the sensation of walking across certain Atacama plains as the closest thing to setting foot on Mars without leaving Earth. This resemblance has led **research teams** to multiply their **field missions** in the Atacama to test instruments, **life-detection methods**, and **scientific protocols** that will later be used during future Mars missions. The Chilean desert has thus become, almost by accident, a genuine full-scale **training ground** for **space exploration**. Engineers now schedule regular expeditions there years in advance of planned missions. *There is something genuinely dizzying about realizing you can study another planet without ever leaving Earth, simply by finding the place that resembles it most closely. This idea fascinates me every time I come back to it.* ## Why it almost never rains in parts of the Atacama ### The decisive role of cold ocean currents The explanation for this extreme dryness starts with an oceanographic phenomenon well known to specialists: the **Humboldt Current**. This ocean current, which carries cold water up from Antarctica along the South American Pacific coast, cools the air above the ocean adjacent to the desert. Cold air holds far less moisture than warm air, which considerably limits the formation of rain-bearing clouds above the coastal region. This cooling also creates a persistent **thermal inversion**, an atmospheric phenomenon that traps cold, moist air near the surface while preventing the vertical convection needed to form storms and typical rainfall. The result: even when moisture is present as coastal fog, locally called **camanchaca**, it almost never turns into actual rain. Locals have learned to harvest this fog directly for drinking water, using simple mesh nets strung between poles. ### The barrier effect of the Andes mountain range The second key factor behind this extreme aridity is purely geographic. The **Andes mountain range**, which borders the Atacama to the east, acts as a natural wall blocking humid air masses arriving from the Amazon and the Atlantic. This effect, known as a **rain shadow**, deprives the desert of any **moisture source** coming from the continent, on top of what is already blocked on the ocean side by the Humboldt Current. Squeezed between these two **climatic barriers**, the Atacama ends up doubly deprived of rainfall, which explains why some weather stations located in its most remote areas can show, over periods spanning several decades, a cumulative measurable rainfall close to zero. Some of these stations have gone entire operational lifetimes without ever registering a single rain event worth recording. *What I find remarkable about this story is the almost mathematical precision with which two independent phenomena, one oceanic and one mountainous, combine to create such a sharply defined climatic extreme.* ## The microscopic life that survives against the odds ### Unexpected extremophile microorganisms One might assume that soil this dry and this exposed to ultraviolet rays would be completely sterile, devoid of any form of life. Research conducted on site over several years reveals exactly the opposite. Teams of microbiologists have identified, in the most arid soils of the Atacama, communities of **extremophile microorganisms** capable of surviving in conditions once thought incompatible with any detectable biological activity. Their discovery forced a rethink of what scientists previously considered the outer limits of habitability on Earth. These organisms, often bacteria or microscopic fungi adapted to extremely low humidity levels, manage to exploit the rare occasions when coastal fog or an exceptional rainfall delivers a minimum amount of water. Some of them enter states of prolonged dormancy, somewhat like **dormant spores**, waiting for **favorable conditions** that may only occur once a decade. This kind of extreme patience has no real equivalent among more familiar terrestrial organisms. ### What these organisms teach us about the possibility of life elsewhere The discovery of these microscopic life forms in one of the most hostile environments on our planet has implications that go far beyond the scope of terrestrial biology. For **astrobiologists**, every new **extremophile species** identified in the Atacama represents an additional **clue** suggesting that life, at least in microbial form, could potentially persist in equally arid and hostile Martian environments. It is precisely this logic that drives **NASA** and other space agencies to fund sample-collection campaigns in the Chilean desert, using **sterilization protocols** and handling procedures modeled on those that would be used during a Mars sample-return mission. The Atacama thus becomes a methodological training ground as much as an object of study in its own right. Engineers rehearse entire sampling sequences there long before any hardware ever leaves Earth. *I find it deeply reassuring, on a personal level, to see that life always finds a way to hang on, even in the most improbable corners of our planet. It feeds a kind of reasoned optimism about what we might one day discover elsewhere.* ## The Atacama as an open-air Martian laboratory ### Instruments tested before their launch into space Beyond simple observation, the Atacama serves as a concrete testing ground for scientific equipment destined for space exploration. Prototype **rovers**, **miniature drills**, and **biological detection sensors** have been deployed there under conditions deliberately similar to those an instrument would encounter on the Martian surface. These trials help identify an instrument's technical weaknesses before it is integrated into a **space mission** costing several hundred million dollars. A flaw caught here, on Earth, is infinitely cheaper to fix than one discovered millions of kilometers away. This pragmatic approach shows how space research, often perceived as distant and abstract, is actually grounded in very concrete terrestrial experiments, carried out in landscapes that have nothing to envy, visually, in certain photographs sent back by rovers currently operating on the red planet. ### A region also studied for its own climate issues Scientific interest in the Atacama isn't limited to its role as a Mars analogue. **Climatologists** also study the dynamics of the **Humboldt Current** and the coastal thermal inversion there, mechanisms that influence not only the local climate but also, more broadly, rainfall patterns along the entire South American Pacific coastline, with repercussions for **agriculture** and **water availability** for local populations. Mining operations in the region, in particular, depend heavily on understanding these long-term water patterns. This **dual scientific role**, both terrestrial and space-related, explains why the Atacama continues to attract significant research funding and **international collaborations** between space agencies, universities, and meteorological institutes, all eager to unlock the last mysteries of this extraordinary desert. *This blend of very concrete local stakes and almost science-fiction-like space perspectives is, to me, what makes this story so captivating to tell.* ## Decades of drought records ### Weather stations that barely register anything Readings taken by various **weather stations** installed in the most remote parts of the Atacama produce numbers that seem almost unreal to anyone living in a temperate or tropical climate. Some of these stations show average annual rainfall totals of less than one millimeter, a level so low it sits practically at the edge of what measuring instruments can reliably detect. Over monitoring periods spanning several decades, some sites have simply recorded no measurable rain event at all, making them unique case studies for **climatologists** seeking to understand the extreme limits of continental aridity. This data feeds scientific databases consulted well beyond Chile's borders, notably by North American and European research teams. ### A mineral landscape shaped by millions of years of drought This near-total absence of rainfall over such a long period has also shaped a distinctive geological landscape, marked by salt formations, natural nitrate deposits, and soils lacking the vegetation cover found in most other deserts on the globe. Some geologists even estimate that certain portions of Atacama soil may not have seen significant rain in millions of years, a climatic age that far exceeds the human timescale. This extreme geological stability, combined with the absence of water erosion, allows researchers to find mineral structures and chemical traces remarkably well preserved, offering a unique window into geological processes that, elsewhere on Earth, would have long since been erased by the action of water. *The thought that a corner of our planet could remain this frozen in time, almost sheltered from ordinary erosion, gives me a sense of vertigo every time I think about it.* ## What to take away from this extraordinary desert ### A climatic extreme that remains rare on Earth In short, certain areas of the **Atacama** rank among the rare places on the planet where the absence of measurable rainfall is counted in decades rather than months, a climatic extreme made possible by the combination of the **Humboldt Current** and the barrier effect created by the **Andes mountain range**. This unique case shows just how much geography and oceanography can, together, shape environments with almost extraterrestrial characteristics. Far from being a simple sterile desert, this region is home to **extremophile microorganisms** whose study directly feeds thinking about the possibility of life elsewhere in the solar system, while also serving as a full-scale testing ground for tomorrow's space exploration technologies. ### A lesson in humility in the face of Earth's extremes This story reminds us that our own **planet** still holds **extreme environments** that can shed light on our understanding of other worlds, without needing to leave Earth's atmosphere at all. The **Atacama** remains a constant reminder that the line between **terrestrial exploration** and **space exploration** is sometimes thinner than we imagine. The next time you hear about a future Mars mission, there is a good chance that some of the **scientific equipment** or protocols used were already tested, years earlier, in this Chilean desert, as arid as it is fascinating, under one of the clearest and most closely studied skies on the entire planet. **By Maxime Marquette, columnist** ## Columnist's transparency note ### Editorial stance I am not a journalist but a **columnist and analyst**. My expertise lies in observing and analysing the geopolitical, economic and strategic dynamics that shape our world. My work is to take political strategies apart, to understand global economic movements, to put the decisions of international actors in context and to offer analytical perspectives on the changes that are redefining our societies. I do not claim the cold objectivity of traditional journalism, which stops at reporting facts. **I claim analytical clarity**, rigorous interpretation and a deep understanding of the complex issues that concern us all. My role is to give meaning to the facts, to place them in their historical and strategic context, and to offer a critical reading of events. ### Method and sources This text keeps the basic distinction between **verified facts and interpretive analysis**. The rule never changes: a factual claim is published only when a verifiable source supports it, and the sources this article actually used are listed under **Sources**, never here. **Primary source families** used by the publication, when the story has them: official statements from governments and international institutions, public statements by political leaders, reports from intergovernmental organisations, dispatches from recognised international news agencies. **Secondary source families**: specialised publications, internationally recognised news media, analyses from established research institutions, reports from industry organisations. When an article cites statistical, economic or geopolitical data, it comes from the institutions that produce it (intergovernmental organisations, central banks, national statistics offices), and the exact institution is named under **Sources**. ### Nature of the analysis The analyses, interpretations and perspectives in the analytical sections of this article are a **critical, contextual synthesis** based on the information available, the trends observed and the expert comments cited in the sources consulted. My role is to interpret these facts, to set them in the context of today's geopolitical and economic dynamics, and to give them a coherent meaning within the larger story of the changes shaping our time. These analyses reflect expertise built through continuous observation of international affairs and an understanding of the strategic mechanisms that drive global actors. This article describes a documented state of affairs on its publication date, not a prediction: later developments may shift its outlook. No update is promised in advance; when an article is corrected or completed, the change is dated in the text. ## Sources ### Primary sources - Jet Propulsion Laboratory, research on terrestrial analogues of Mars — 2026 - NASA Science, climate and astrobiology studies — 2026 - National Oceanic and Atmospheric Administration, data on the Humboldt Current — 2026 ### Secondary sources - National Geographic France, environment — 2026 - Futura Sciences, planet section — 2026 - Sciences et Avenir — 2026 --- Source: Maxime Marquette, MadMax. When citing, name the author and link https://mad-max.co/en/article/des-zones-du-desert-d-atacama-n-ont-jamais-vu-une-goutte-de-pluie