Looking up at the night sky and discovering those persistent white lines can be unsettling for many. As a result, social media and discussion forums have fueled all sorts of theories about so-called "chemtrails," especially when they appear at night. What is this phenomenon really about? Is there any scientific basis for the idea that we are being secretly sprayed by airplanes, or is it all the result of misinformation and unfounded fears?
Let's dive into the fascinating debate about contrails in the night sky, debunking myths and explaining in detail what really happens when you see one of these trails in the wake of an airplane, especially at night. Get ready to discover, with precision and clear language, everything you need to know to avoid being fooled by appearances or the hoaxes that are increasingly circulating on the internet.
The genesis of the myth: Why do chemtrail theories arise?
Belief in chemtrails didn't emerge out of nowhere, but rather stems from a mix of scientific ignorance, fear of the unknown, and the rapid spread of ideas through the internet and social media. For decades, rumors have linked airplane contrails to alleged secret programs dedicated to modifying the weather, controlling the population, or even altering the human mind.
One of the main reasons for the spread of these theories has been the rise of information—and misinformation—online. Social media and blogs have amplified messages and suspicions, often using spectacular images of skies covered in white streaks as supposed "proof" of a global covert plot. Thus, the word "chemtrail" (a contraction of "chemical trail") has quickly become popular, clashing with real-life technical terms like "contrail" (from "condensation trail").
Especially after extreme weather events such as droughts or heavy rains, or in contexts of great social uncertainty, chemtrail theories often resurface with greater force. Recently, they have even reached political debates in official venues, such as the Spanish Congress of Deputies, where questions have been posed to the government regarding alleged weather manipulation from the air.
What are the trails we see in the night sky really?
The trails left by airplanes, both day and night, are mainly artificial clouds created by the condensation of water vapor contained in the exhaust gases of jet enginesWhen an aircraft flies at high altitudes (between 8.000 and 12.000 meters, where temperatures can drop to -40°C), the hot, water-vapor-saturated gases it expels mix with the cold, dry air around it.
If the mixture reaches the necessary saturation level, this vapor condenses rapidly and forms tiny ice crystals. The result is a bright white line that can travel several kilometers behind the aircraft and, under certain atmospheric conditions, remains visible for minutes or even hours.
The key is the temperature and humidity of the atmosphere in the flight zone. If the air is very dry, the contrail dissipates quickly; if it is humid and cold, the contrail can expand, persist, and even appear as a large cloud. Therefore, We can't always see the trail when an airplane passes by, and not all trails last the same amount of time..
This phenomenon is especially noticeable at night, since solar radiation does not interact as much with the ice particles and atmospheric conditions can further favor the persistence of trails. Furthermore, the absence of clouds and the clarity of the night sky make these lines easily visible and sometimes more striking than during the day.
The role of air traffic and technological evolution in the abundance of contrails
A determining factor in the perception that “there are more contrails now than ever” is the spectacular increase in air traffic over the past few decades. Every year, millions of commercial flights cross the sky at different times of the day and night, increasing the chances of seeing contrails, especially in regions near busy air routes.
As if that weren't enough, jet engine technology has evolved, favoring the formation of contrails under certain circumstances. Modern, more efficient engines exhaust gases at lower temperatures, which expands the range of weather conditions in which water vapor condensation can occur in the form of a trail.
Science vs. Myth: What Do Experts Say About Chemtrails?
Conspiracy theories about chemtrails have been thoroughly reviewed and refuted by the scientific community in multiple international studies. One of the most relevant studies, published in 2016 by the Carnegie Institution for Science, the University of California, Irvine, and Near Zero, consulted 77 experts in atmospheric chemistry and geochemistry. The result was conclusive: 76 of the 77 scientists said they had never found evidence of a secret global chemical spraying program..
The samples and analyses cited by conspiracy theorists have never produced solid, independent, or verifiable data. Many laboratories have ruled out the possibility of dispersing elements such as barium, aluminum, or strontium from high altitudes, as these compounds are neither soluble nor dispersed efficiently through the air, and their application would be logistically and scientifically unfeasible.
Authorities such as the Spanish State Meteorological Agency (AEMET), the United States Air Force, and the U.S. Environmental Protection Agency (EPA), among others, have publicly reiterated that there are no plans to modify the weather using commercial or military aircraft. No independent laboratory, environmental monitoring network, or international organization has found evidence of illegal or clandestine activities related to chemtrails.
Geoengineering: between science and media confusion
The term 'geoengineering' is often confused with chemtrail theories, but it is essential to clarify the differences. Geoengineering encompasses scientific proposals—most of which are still in the experimental or theoretical phase—aimed at locally modifying the climate to reduce global warming, such as cloud seeding or the use of reflective aerosols in the atmosphere.
In practice, large-scale geoengineering experiments are extremely limited and monitored by national and international organizations. For example, cloud seeding, which uses silver iodide in the hope of inducing rain, has only been used in very specific areas and under controlled conditions. Furthermore, numerous reports from the World Meteorological Organization conclude that these techniques produce few measurable changes and are certainly far from the magnitudes attributed to the chemtrail conspiracy.
Can aircraft contrails really affect the weather?
The question is not trivial, and here science does recognize certain effects, although very far from what the hoaxes suggest. Persistent aircraft contrails can contribute to the formation of high clouds (artificial cirrus clouds), which, when accumulated in large quantities, do have a modest but significant effect on Earth's radiation.
During the day, these clouds reflect some of the solar radiation (albedo effect), which can help to slightly cool the surface. However, at night, the same clouds act as a blanket, preventing the heat accumulated during the day from escaping into space, making some nights warmer. This phenomenon was confirmed after the closure of US airspace following the attacks of September 11, 2001, when temporary variations in the daily temperature cycle were observed due to the lack of flights.
However, this does not imply drastic alterations or hidden manipulations of the climate. The global impact of contrails is limited compared to other factors, such as greenhouse gas emissions. It is estimated that all commercial aviation accounts for around 2% of the planet's total CO2 emissions.
Are there differences between contrails and chemtrails?
For science, there is no real difference. Proponents of the myth often claim that chemtrails persist longer or have a denser, more bizarre appearance than normal contrails. However, experiments show that the duration and appearance of a contrail are determined solely by atmospheric factors, not by supposed chemical additives.
A long-lasting, expanding, cloud-like contrail simply indicates that the atmosphere was very humid and cold at that point and altitude. Thus, water vapor and ice crystals do not dissipate quickly, but can remain and grow in volume. In contrast, in dry air, the contrail evaporates shortly after forming, regardless of the engine's composition or the flight's intention.
The influence of social media and the bubble effect
A key aspect of the spread of the chemtrail theory is the bubble effect generated by social media. Closed groups on platforms like Facebook, forums, and video channels allow people who firmly believe in the existence of chemtrails to share information, photographs, and experiences, providing feedback and reinforcing their beliefs, even when there is no external evidence to support them.
Surveys in Western countries show that around 17% of the population fully or partially believes in the existence of chemtrails. This percentage remains stable thanks to the proliferation of shocking images, personal testimonies, and a widespread distrust of official institutions.
Within these communities, scientific evidence is often dismissed or reinterpreted as part of the alleged conspiracy. Personal testimonies, such as home analyses of rainwater, soil, or hair, are circulated as irrefutable evidence, although they are never verified by independent experts or published in peer-reviewed scientific journals.
Variants of the myth: health, climate and social control
The chemtrail myth has mutated over the years and adapted to contemporary concerns. From the alleged introduction of diseases, to mind control, to the deliberate creation of droughts or artificial rainfall, everything fits into this chameleon-like narrative.
During the COVID-19 pandemic, for example, hoaxes emerged accusing governments of using airplanes to spray biocides over the entire population. These messages were based, again, on a mixture of real facts (such as the timely disinfection of closed spaces) and misinterpretations or deliberate manipulations.
Some variants of the myth mention strange illnesses attributed to exposure to these trails, such as the so-called 'Morgellons disease' or the appearance of strange 'angel hair' falling from the sky. However, the presence of unknown substances in these samples has never been collected, analyzed, and scientifically proven, and the associated diseases have no epidemiological correlation with air traffic.
And what about photos of tanks or drums on airplanes?
Images circulating online, purportedly showing chemical tanks inside aircraft, are often photographs of aircraft undergoing testing or equipped for weight and balance simulation experiments. For example, the famous image of former German Chancellor Angela Merkel inside an airplane surrounded by drums corresponds to a cargo test to simulate passengers on test flights, not a secret spraying program.
Other specialized aircraft photographed with spraying systems are used for firefighting, oil spill cleanup, or crop planting—never for high-altitude flights over cities and towns. The confusion is due, once again, to a lack of context and a tendency to see hidden connections where there are only perfectly documented technical procedures.
Is it possible to spray from great heights?
According to agricultural aviation experts, dropping chemicals from altitudes of over 10.000 meters—as commercial flights do—is completely ineffective and unfeasible. Crop-spraying aircraft operate just a few meters above the ground, precisely to ensure the products reach their target. Any attempt to disperse a product from high altitude would be immediately dispersed by winds and turbulence, making it impossible to reach the desired point on the ground.
Furthermore, the amount of substance that would be necessary to reach toxic concentrations over large areas would be so enormous that it would be logistically, economically, and technically unmanageable. All this without taking into account the traceability provided by modern flight tracking and environmental quality control systems.
The importance of separating facts and beliefs
Chemtrail theories actually challenge us to differentiate between perception, fear of the unknown, and solid, verifiable scientific explanations. In an increasingly interconnected world, information—and misinformation—travels faster than ever, and the temptation to believe in conspiracies can increase in times of uncertainty.
Understanding how night trails form, what factors make them more or less visible, and the limits of our ability to modify the weather is essential to avoid falling into false beliefs. Open and verifiable science has shown that chemtrails as a secret program do not exist, while the increase in trails can be explained by perfectly logical and verifiable reasons.
Environmental control and stewardship—and, of course, the debate over the climate impact of aviation—is real, but it has nothing to do with supposed secret maneuvers to control the world from the skies.
The white lines that crisscross the sky, even on the clearest nights, are not evidence of an international conspiracy or the reflection of a hidden threat, but rather the visible result of scientific advancement, technological progress, and increased global mobility. Understanding them, far from instilling fear, should help us value knowledge and a critical spirit in a society saturated with information but often in need of effective filters to separate reality from myth.