‘Real-life Project Hail Mary’: Scientists discover a hidden fungal network beneath Earth stretching 110 quadrillion kilometres
Beneath forests, grasslands and even the soil in our gardens lies an extraordinary hidden world that most people never see. Scientists have now mapped a vast underground network of microscopic fungi stretching an estimated 110 quadrillion kilometres across Earth’s topsoil, a distance so immense that it could reach the Sun nearly a billion times. The discovery has drawn comparisons to Astrophage, the mysterious organism from Andy Weir’s science-fiction novel Project Hail Mary. While the comparison is more metaphor than reality, researchers say these ancient fungal networks quietly support much of life on Earth, helping plants grow, storing carbon and maintaining the health of entire ecosystems.
Inside Earth ‘s hidden giant fungal network
The discovery comes from a major international study led by researchers associated with the Society for the Protection of Underground Networks (SPUN). Using more than 16,000 soil samples and advanced computer modelling, scientists created the most detailed global map yet of arbuscular mycorrhizal fungi, a group of fungi that live in partnership with plant roots.The study revealed that these microscopic fungal threads, known as hyphae, collectively stretch around 110 quadrillion kilometres through the world’s soils. Although invisible to the naked eye, they form one of the largest biological systems on Earth.Importantly, scientists did not find a single giant fungus circling the planet. Instead, the figure represents the combined length of countless fungal networks spread across ecosystems worldwide.
Why are people comparing it to Project Hail Mary?
The comparison comes from Project Hail Mary, the bestselling novel by Andy Weir, which introduced readers to Astrophage, a microscopic lifeform capable of storing and transferring enormous amounts of energy.The newly mapped fungal networks are not alien organisms and they do not behave like Astrophage. However, researchers say the comparison resonates because both involve hidden biological systems operating on an immense scale.Like the fictional organism, these fungi move resources across vast networks, support larger ecosystems and possess an influence far greater than their microscopic size suggests.In reality, these underground fungi have been performing their role on Earth for hundreds of millions of years.
What are arbuscular mycorrhizal fungi?
Arbuscular mycorrhizal fungi, often shortened to AM fungi, form mutually beneficial relationships with approximately 70% of all land plants.The partnership works like a natural trade agreement. Plants produce sugars through photosynthesis and provide some of that energy to the fungi. In return, the fungi help plants absorb water and essential nutrients such as phosphorus and nitrogen from the soil.The fungi extend far beyond plant roots, acting as an underground extension of a plant’s root system. This allows plants to access resources that would otherwise remain out of reach.Scientists believe these fungi played a crucial role in helping plants colonise land roughly 475 million years ago.
The hidden ‘wood wide web’ beneath our feet
Researchers often refer to these fungal systems as the “wood wide web” because they connect plants through vast underground networks.The fungal threads can link multiple plants together, allowing nutrients, water and chemical signals to move through the soil. Some studies suggest plants may even use these networks to share resources or send distress signals when threatened by disease, drought or insect attacks.Although scientists continue to debate exactly how much information travels through these systems, there is broad agreement that they are fundamental to ecosystem health.Without them, many plants would struggle to survive.
Why the discovery matters for climate change
One of the study’s most important findings concerns carbon storage.Researchers estimate that Earth’s topsoils contain approximately 300 megatons of carbon locked inside these fungal networks. That is roughly four to six times the total mass of all humans on the planet.The fungi also help move carbon underground by transporting carbon-rich compounds from plants into the soil. Some estimates suggest these networks help sequester up to one billion metric tons of carbon each year, making them an important natural ally in the fight against climate change.Because carbon stored underground is less likely to enter the atmosphere as carbon dioxide, healthy fungal networks can play a significant role in regulating Earth’s climate.
Where are these fungal networks most abundant?
The study found the densest fungal networks in natural ecosystems such as grasslands, wetlands and floodplains.Large wetland systems, including Florida’s Everglades and South Sudan’s Sudd wetlands, emerged as particularly important hotspots.These regions support rich fungal communities that contribute to biodiversity, soil health and carbon storage.Scientists say protecting such ecosystems could have benefits far beyond preserving wildlife, as the underground fungal networks they contain provide critical environmental services.
Why scientists are concerned about agriculture
While the findings highlight the importance of fungal networks, they also reveal signs of decline.Researchers found that intensively farmed croplands contain significantly fewer fungal networks than nearby natural ecosystems. Practices such as deep tilling, excessive fertiliser use and soil disturbance can damage fungal communities and reduce their abundance.According to the study, fungal concentrations in agricultural land can be nearly 50% lower than in undisturbed environments.The loss of these fungi may make crops more dependent on synthetic fertilisers and less resilient to drought and other environmental stresses.
What could this mean for the future?
Scientists believe the new map will help identify areas where fungal networks need greater protection and restoration.Protecting these hidden ecosystems could improve food security, strengthen plant resilience, reduce fertiliser use and enhance carbon storage. Researchers argue that conservation efforts have historically focused on animals, forests and visible ecosystems while largely overlooking the vast biological infrastructure hidden underground.The study suggests that some of Earth’s most important ecosystems are not found above ground at all.
A hidden world that supports life on Earth
For centuries, people have viewed soil as little more than dirt beneath their feet. The new research paints a very different picture. Beneath nearly every forest, grassland and field lies a sprawling fungal network that helps sustain plants, regulate climate and support entire ecosystems.While comparisons to Project Hail Mary may capture the imagination, the reality is arguably just as remarkable. Scientists have revealed a hidden living system stretching 110 quadrillion kilometres across the planet, quietly helping life on Earth thrive while remaining almost entirely unseen.
