For Years, Human Beings Have Been Asking The Question, Are We Alone In This Vast World? And Despite Many Attempts, It Has Not Been Able To Answer This Question Definitively.
Extraterrestrial Life, Since the twentieth century, with the advancement of space technology and the beginning of the space age, extraterrestrials have become a hot topic for researchers and popular culture. Since the middle of the twentieth century, rumours of objective evidence of tiny green creatures have circulated.
These rumours spread quickly; So much so that they became a fascinating subject for science fiction stories and novels, and movies. Scientists, on the other hand, began strenuous efforts to search for extraterrestrial beings and life. These efforts spanned all extraterrestrial life, from microbial organisms to intelligent extraterrestrial life.
Today, with the advancement of telescope technology and more probes, the search for extraterrestrial beings and life continues. Despite the lack of precise results, researchers do not stop searching and always ask whether we in this infinite world alone Are? But they have not yet been able to provide a convincing answer to this question.
This article will focus on speculations, efforts, and research about extraterrestrial beings, from serious efforts to search for extraterrestrial life in the solar system and distant galaxies to rumours and evidence of unidentified flying objects (UFOs) and their role in popular culture.
The titles you will read in this article:
- What is extraterrestrial life?
- Earthly life; Life search pattern
- Extraterrestrial life in the solar system
- Life on extrasolar planets
- Intelligent extraterrestrial life
- Extraterrestrial life search methods
- Extraterrestrials in ancient civilisations
- Unidentified flying objects (UFOs)
- History of UFO
- Extraterrestrials in popular culture
What is extraterrestrial life?
Extraterrestrial life is hypothetical life that may exist outside of Earth. This life has no earthly origin and includes all kinds of life from simple prokaryotes to intelligent beings or even intelligent beings; Creatures that may be even more advanced than humans.
According to many scientists, the possibility of extraterrestrial life, including microscopic organisms, is very high worldwide. This hypothesis is based on the vastness and corresponding physical laws of the visible universe. According to the theory put forward by Carl Sagan and Stephen Hawking, life may not exist anywhere but on Earth.
Since the 1950s, astronomers have hypothesised the life belt around stars. The Belt of Life is the possible point for the growth and prosperity of life around a star. Numerous discoveries of the Belt of Life in 2007 provided the basis for estimating billions of Earth-like planets. By 2013, few planets discover within the belt of life. Still, according to astronomers on November 4, 2013, based on data from the Kepler spacecraft, there are probably 40 billion Earth-sized planets in the stellar life belt in the Milky Way alone, 11 billion of which are in orbit similar to the Sun.
In the Milky Way alone, 11 billion planets are in orbit, similar to the Sun.
Earthly life; Life search pattern
Life on Earth needs water as a solvent for biochemical reactions. Adequate amounts of carbon and other elements, along with water, allow living organisms to form on Earth-like rocky planets. Ammonia-based life has been suggested as another type of life, But this solvent is not as suitable as water for life. It makes sense for other life forms to exist with different solvents, such as methane, ethane, or propane. Approximately 29 chemicals play an active role in the life of terrestrial organisms.
About 95% of living organisms are based on only six elements: carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur. These six elements form the basic building blocks of terrestrial life; While a large part of the remaining elements can be found in small quantities.
The unique properties of carbon make it unrivalled even on other planets. The carbon atom has the unique property of forming four strong chemical bonds with other atoms, including other carbon atoms. These covalent bonds have a direction in space; As a result, carbon atoms can form the skeletons of complex three-dimensional structures such as nucleic acids and proteins.
Carbon plays a more significant role in the formation of various compounds than any other element. The high flexibility of this element and its abundance in the visible world has made it the dominant element for the chemical composition of life on other planets.
Extraterrestrial life in the solar system
So far, many explorations have been made on the planets of the solar system, especially Mars. Many of these discoveries were devoted to the search for life on the planets and moons of the solar system.
The potential for life is more outstanding on rocky planets such as Mars and icy moons. In general, any point in the solar system with water, ice, volcanic activity, atmosphere, and surface fluids can form extraterrestrial life. According to NASA’s 2015 Astrobiological Strategy, life on other worlds is likely to include microbial life, and any different complex life is based on microbial life.
Life on Mercury
NASA’s MESSENGER spacecraft observed evidence of water ice on Mercury. According to a report released in March 2020, there is a possibility of habitat and life formation in parts of the planet.
Life on the planet can be in the form of tiny microscopic organisms. Mercury is very close to the Sun, and its conditions are not conducive to the formation of more complex structures of life, But there is still more reliable data on life on the planet, and no direct evidence has been found.
Life on Venus
Venus was like the earth in the distant past; But gradually, with the intensification of weather conditions and the effect of greenhouse evasion, it returned to its current state. Until a few years ago, no one even thought of discovering life on this hellish planet; But with the discovery of phosphine gas in the planet’s atmosphere, the sheet turned, and all eyes were drawn to the earth. The discovery of this gas increased the possibility of life in the clouds of Venus.
Phosphine is an unpleasant gas, most of which is produced by biological activities. Some scientists have suggested that the gas may have been caused by possible volcanic activity on Venus. Still, others see the evidence as insufficient and believe the gas may be of biological origin. With the limited data available, it is difficult to comment on the accuracy of the discoveries.
NASA is currently working on two Venus exploration projects. In the coming years, this data will be able to turn speculation into reality. Venus’ life will not go beyond microbial life because the planet’s surface is not suitable for the growth of living organisms due to extreme temperatures and the presence of toxic gases.
Life on Mars
Mars is one of the most Earth-like in the solar system. The planet is equivalent to 24.5 Earth hours then It has polar ice caps, seasonal variations, and a wide range of surface features. Despite the deployment of numerous probes and astronauts, no form of extraterrestrial life has yet been found; But there is ample evidence that has led scientists one step closer to the clue to life. Mars is an excellent place to look for life for several reasons.
Primarily, the planet had liquid water rivers and surface lakes billions of years ago, and we know that the thick Martian atmosphere at that time kept the earth warm.
Numerous astronauts are currently exploring the surface of the Red Planet. For example, the Perseverance probe is looking for signs of Mars’ past life.
The probe collects samples that will one day return to ground labs.
On the other hand, there are groundwater resources on Mars. Water as the fluid of life increases the potential for the discovery of microbial life. Large-scale research is currently underway on radar observations of these water resources, which are miles below the surface of Mars.
Under similar conditions on Earth, bacteria were discovered in groundwater; As a result, it is likely to increase for Mars as well. Access to the water below the surface of Mars is difficult; But with the advancement of technology, it will not be impossible.
Life on the moon, the moon of the earth
In past centuries, the moon was thought to be the host of extraterrestrial beings. About 3.5 to 4 billion years ago, the moon had a magnetic field and enough atmosphere and liquid water. There is still water in parts of the moon that will use in future lunar travel projects to provide astronauts with resources. . So far, no native life has been found, especially in the rocks and soil of the moon.
The position of the blue cover of the moon
Life in Ceres
Ceres, the largest giant asteroid and the minor dwarf planet in the solar system, can host groundwater. This dwarf planet is located between Mars and Jupiter. NASA’s Dawn probe studied the asteroid between 2015 and 2018. Scientists have not yet thoroughly analysed the data from this study. Still, according to numerous studies in recent years, there is probably an underground ocean at a depth of 40 km of this asteroid, which has stretched for hundreds of kilometres.
This ocean is almost salty, preventing water from freezing and reaching temperatures below zero degrees. Down also found evidence of biological compounds in Ceres that could form the raw materials of life.
But Ceres’ habitability comes with many questions. The evidence for groundwater and biomaterials is entirely new. Even if there is all this evidence, there is a need for energy and heat so that water and biomaterials can react to form life.
Even so, finding life on the asteroid requires digging to the depths and accessing and exploring water. Finally, Ceres is 13 times smaller than Earth, and it is not yet clear if its gravity can affect life. And since Earth is a habitable compass, Ceres’ small size may not be a positive feature.
Life in Europe
Europe, Jupiter’s moon, has 16 to 21 km thick icy crusts that cover much of the moon’s subsurface oceans. These oceans are warming due to tidal forces. According to the hypotheses, the increase in heat can create an internal circulatory system that leads to the movement of water and the regeneration of surface ice in a regular manner.
It means that the ocean floor interacts with its surface, and if you do not need to dig to great depths to study life in the lower oceans. Scientists have also found sources of clay-like minerals that are related to European biomaterials.
Space rays are also thought to produce oxygen when they hit the icy surface of Europe; This element eventually finds its way to the lower oceans and may play a role in shaping life.
In general, Europe has all the raw materials of life. One of the JUICE mission goals is to scrutinise Europe, and another mission dedicated to Europe-specific scrutiny is Europe Clipper.
A spacecraft that flies at low altitudes from the moon will study its surface features and subsurface environment. The clipper will be launched in 2024 and will reach Europe in 2030.
Life on Titan
Titan is Saturn’s largest moon. This moon has completely different characteristics from other moons and worlds in the solar system. After Venus and Earth, Titan is the only rocky world with a stable and thick atmosphere. The moon also has surface liquid lakes and rivers, But these seas are not water. They are made up of methane and other hydrocarbons.
Titan is rich in biomaterials as well as raw materials needed for life. There may also be subsurface oceans on the moon made up of water, But this claim requires further investigation.
NASA’s Dragonfly mission is to explore Titan. It has an unman helicopter probe that directly examines Titan’s atmosphere during its mission and uncovers its biological and chemical composition. Dragonfly will be launched in 2027 and will reach Titan by 2034.
Life on Enceladus
Enceladus is the sixth-largest moon of Saturn, completely covered with ice and has one of the most reflective surfaces among the solar system objects.
Activities below the surface of the moon are underway. Glaciers emitted from the surface of Enceladus contain thousands of different compounds, including saltwater, ammonia, and biomolecules such as methane and propane. Enceladus is thought to have a subsurface saline ocean.
According to NASA evidence, the subsurface hydrothermal activity provides the heat source needed for life to form and evolve. In recent years, several proposals have been made to study Enceladus, all of which are dedicated to the search for signs of life below the surface of Enceladus.
Life in Ganymede
Ganymede is the largest moon of Jupiter and the largest moon in the entire solar system. Like several other moons in the Zohli and Jupiter systems, this moon has an icy cover; But beneath this frozen crust of the ocean is the saline surface water, which may be more than the total water of the Earth’s oceans.
Naturally, water can be a potential host for life. The moon also has a dilute oxygen atmosphere. Ganymede also has a unique feature that many moons in our solar system lack: the magnetic field. The presence of a magnetic field is essential to protect the world from the sun’s harmful rays.
But Ganymede is not perfect. Exploring its subsurface ocean is difficult; As a result, even if there is life on this moon, it can hardly be found. So far, no specific mission has been assigned to Ganymede; But in 2032, the JUICE probe will take a closer look at the moon.
The probe will use its radar to detect possible clues to life on the planet accurately.
Life in Callisto
Callisto has the oldest surface in the solar system and is another moon with a subsurface ocean at a depth of approximately 250 km. The moon also has a thin atmosphere of hydrogen, carbon dioxide and oxygen, similar to Earth in terms of diversity.
But the possibility of life in Callisto is not as high as in other worlds; Because this moon is icy. The opportunity to examine Callisto more closely will gain through the JUICE mission.
Life in Iowa
With more than 400 active volcanoes, Ivo is the most geologically active world in the solar system. One of the reasons for this activity is the tidal forces from inside IoT, which are caused by the gravitational pull between Jupiter and other moons.
Volcanic activity creates a massive coating of sulfur and sulfur dioxide on the surface and atmosphere of Iowa. There is also the possibility of a subsurface ocean in Iowa; But the structure of this ocean is made of magma, not water.
Life on Ivo is almost unlikely; However, areas below or below the Iowa level are not volcanic activity. Places with milder temperatures where the most complicated forms of life are formed.
It is impossible to study this life directly; But if you are lucky. The best opportunity to explore Iowa is the IVO (Ivo Volcanic Observer) mission, which, if approved, will be launched in 2029.
Life in Triton
Much of Triton’s surface is made up of solid nitrogen, and its crust is made up of water ice.
The moon also has icy mantles. Despite the extreme cold, heat activity appears to have been formed by tidal forces within the planet. These forces are created by the gravitational pull of Triton and Neptune and can help warm water and raise biomaterials.
But finding life on Triton is a far-fetched goal. Only Voyager 2 explored the moon in 1989. The best opportunity to explore Triton would be the Trident mission, launched to Venus after this decade’s NASA mission.
Life on extrasolar planets
More than 4,000 extrasolar planets have been discovered since 1992. Scientists on these planets are also looking for an answer to their age-old question: Are we alone? What makes an extrasolar planet habitable, and what conditions are necessary for life to grow on these planets?
In assessing the potential for life, in other words, scientists first look at the planet’s size, mass, and atmosphere. According to many astronomers, habitable extrasolar planets are within their planet’s life belt. Some astronomers have limited their search to rocky planets within their stellar life belt.
The Kepler Space Telescope has identified several thousand candidate planets, of which 11 per cent may be false positives. On average, there is at least one planet per star.
At least one in five Sun-like stars has Earth-like planets in their life belt. The nearest world is only 12 light-years from Earth. Assuming there are 200 billion stars in the Milky Way, the number of Earth-like planets could reach 11 billion, and if we include the red dwarfs in this calculation, that number will reach 40 billion.
The nearest known extrasolar planet is Proxima Centauri b, located 4.2 light-years from Earth in the southern part of the constellation Centaurus.
In general, smaller stars, including red dwarfs, are the most common stars in the Milky Way, and their life belts are very close to the stars. One such example is the TRAPPIST-1 system.
The planets in the life belt of these stars are very close to their lead and are exposed to intense X-rays and ultraviolet rays, which are hundreds of thousands of times more intense than the rays received by the Earth.
Life on other planets may bear no resemblance to Earth; But at least we can use the available data to search for the life we know; Because it is easier to find such a life. Many of the known rocky planets are about the size of Earth, which could increase the likelihood of life on such planets.
On the other hand, most Earth-like worlds have been observed around red dwarf stars; Discovering Earth-like planets in the orbit of sun-like planets is difficult. Red dwarfs emit powerful tongues from their surface.
These tabs can destroy the life of planets in orbit around these stars.
Given the conditions and evolution of Earth life from about 4 billion years ago, it can conclude that stars like the Sun provide better conditions for life and are better candidates for the search for extraterrestrial life. On the other hand, G-type yellow stars, like the Sun, have a shorter lifespan and are fewer in the Milky Way.
Conceptual image of the planet Proxima Centauri b. This rocky planet is the closest extrasolar planet to Earth, located in its stellar life belt.
Intelligent extraterrestrial life
Intelligence and technology have been created on Earth during stable periods of the sun’s life. There are several benefits to intelligence and technology; But these developments could lead to ecological catastrophes, depletion of natural resources and even nuclear war. Despite such disasters, the Earth’s physical environment has remained almost stable for billions of years.
Many steps are required to evolve intelligence and technology, and not all habitable planets have this capability. On the other hand, according to some experts, extraterrestrial civilisations are destroyed by reaching a certain level of technology.
It is estimated that there are billions of suitable planets in the galaxy and considering that the living conditions of some planets are good and have evolved billions of years. Even a tiny part of technological civilisations have safely passed the early stages of technical maturity, the number of intelligent civilisations is It will still be a lot.
The number of such civilisations can hardly be estimated. Opinions differ; But according to the best guess, there are almost one million civilisations in the Milky Way at the level of Earth technology or beyond. If these civilisations were randomly distributed in space, the distance between us and the nearest culture would be nearly 300 light-years.
Therefore, the one-way communication of information between us and another civilisation will take at least 300 years, and if we receive a response, it will take 600 years.
The Drake equation is used to estimate the number of extraterrestrial civilisations active in the Milky Way. Frank Drake proposed this equation in 1961. Of course, his goal was not just to measure the number of cultures; Rather, it sought a way to simulate a scientific dialogue at the first SETI Scientific Meeting.
One of the main challenges of Drake’s equation is that astronomers have no actual numbers for their variables; As a result, any calculations related to Drake’s equation remain in the estimation range. Of course, discoveries in some areas have led astronomers to develop better ways to solve the equation.
The Fermi paradox is derived from the name of Enrico Fermi (Italian-American physicist). This definition refers to the contradiction between the lack of evidence for extraterrestrial civilisations and related estimates of their probability (including optimistic assessments of the Drake equation).
This paradox raises the following facts:
- There are billions of sun-like stars in the Milky Way.
- Most likely, some of these stars are the size of Earth-like planets in their life belt.
- Many of these stars, and consequently their planets, are much older than the Sun. If Earth were ordinary planets, the intelligent civilisation of some worlds might have formed much earlier than Earth.
- Some of these civilisations have mastered the technology of interstellar travel and are far ahead of terrestrial humans.
- Even at the slow speed of interstellar travel, the entire Milky Way galaxy can traverse in a few million years.
- Because many of the Sun-like stars are billions of years older than the Sun, Earth may have been visited in the past by extraterrestrial civilisations, or at least their explorers.
- But there is no convincing evidence for all this.
Numerous attempts have been made to explain the formal contradiction. This paradox raises three possibilities:
- Intelligent civilisations are very rare.
- The life of such societies is short, and they usually destroy themselves.
- There are intelligent civilisations, But man cannot see them.
Extraterrestrial life search methods
The scientific search for extraterrestrial life is done in two ways, direct and indirect.
The search for scientists to discover biological artefacts by examining the surfaces of planets and meteorites falls into the category of direct methods; But despite the discovery of materials and elements necessary for life, there is still no direct evidence of microbial life on the surface of any of the objects in the solar system, and missions and discoveries continue.
On the other hand, evidence and discoveries related to the Earth’s past significantly impact the perception of Earth-like extrasolar planets and even the formation of other solar system objects.
In August 2011, NASA surveyed meteorites found on Earth to show that DNA and RNA components (adenine, guanine, and related biological molecules) could be of extraterrestrial origin.
Projects such as SETI (Intelligent Extraterrestrial Intelligence Search) monitor the galaxy to find the interstellar electromagnetic signals of other civilisations. There is no guarantee that radio signals will emit the earth’s direction if there is an advanced civilisation.
The amount of time it takes for a signal to travel through space means that any signal detected has been emitted in the distant past. The presence of heavy elements in the starlight spectrum is another biological effect of discovering extraterrestrial civilisations.
SETI uses radio telescopes to track extraterrestrial signals.
Developing the Statistical Society: A group of researchers at the University of Manchester increased the statistical sample of the search for extraterrestrial life from 1,400 stars to 280,000 stars.
According to the results, less than 0.04% of stellar systems can host advanced civilisations with the same or slightly more advanced technologies than 21st-century humans. For the first time, researchers used new filters and conditions to search for intelligent life.
In this search, it is assumed that potential forms of intelligent life have advanced telecommunication technology.
According to these criteria, researchers can only discover advanced and intelligent civilisations that use radio waves to communicate, and therefore can not simply find a simple form of life or non-advanced civilisations.
The researchers recalculated the constraints on the stars in the radio telescope’s field of view, based on data from the European Space Agency’s Gaia spacecraft. The Gaia spacecraft has so far measured distances of more than one billion stars. By selecting distant stars (up to a distance of 33,000 light-years), they can increase the range of possible choices from 1327 to more than 288,000 stars.
Examination of extrasolar planets:
According to NASA research, if there is an advanced extraterrestrial civilisation in a nearby star system, its existence can detect through atmospheric pollution. To do this, scientists must look for nitrogen dioxide gas produced on Earth by burning fossil fuels or through non-industrial sources such as biological activity, lightning, and volcanoes.
Sending a Message to Extraterrestrial Intelligence (METI):
Most of these efforts were organised by the Extraterrestrial Intelligence Research Institute (SETI) in California, but no success has been achieved. Some scientists are looking for a more active program called Messaging to Extraterrestrial Intelligence (METI). This app is not just about listening; It involves sending powerful messages to other stars and communicating. It speeds up the search and may even receive signals.
Extraterrestrials in ancient civilisations
Many ancient monuments on earth are very heavy, vast and complex. According to old beliefs, extraterrestrials have played a role in doing such works. This claim has never been substantiated, But it has some exciting narratives in popular culture.
There are structures such as the pyramids of Egypt, the Nazca Lines, and many works that some believe build according to specific instructions. The creatures that made these massive structures may have come from other planets. It is exciting and fun to think that extraterrestrials have visited Earth one day.
However, humans have also shifted the boundaries of exploration and gained access to planets such as Mars. Still, the truth is that there is no evidence that extraterrestrials were here and that supernatural definitions of human achievement mean ignoring the achievements of antiquity in managing and constructing impressive structures on Earth. Here are some points that have been thought to have been made by extraterrestrials for years:
Sioux The Castle
Located in Peru, this temple is made of several stones stacked on top of each other like a puzzle. Some people believe that in ancient times, they used the help of their extraterrestrial friends to build this building. The 1000-year-old walls of this building are made of stones, each weighing approximately 36 tons, and after a distance of 32 km, they have been raised and placed on top of each other with high precision. How can an ancient culture achieve this engineering achievement?
Archaeologists have recently found traces of rope and lever systems used by the Inca Empire to transport stone; This system depends more on power and genius than extraterrestrial architects.
A high, dry plateau southeast of Lima shows white lines engraved on the body of the desert. These lines look random; But by connecting them, you can get 300 geometric shapes and 70 shapes of animals, including spiders, monkeys and hummingbirds. The enormous shapes reach a length of 360 meters, which can be seen better from the aerial view.
Scientists believe that these lines are almost two thousand years old. Their age, size, appearance, and mysterious nature make them one of the best dubious examples of extraterrestrial construction on Earth. Otherwise, how can an ancient civilisation make these plans without flying and seeing them from the aerial view, and why should it do so?
Archaeologists believe that these lines were created by removing the top layer of rocks and showing whiter layers below. Nazca lines first study in the early 1900s.
Recent research shows that these lines are used for religious ceremonies or celebrations related to water and fertility. In addition to the aerial view, their shapes can be seen from the surrounding hills.
The pyramids of Egypt
Outside Cairo in Giza, Egypt’s most famous pyramids rise from the desert. The Pyramids of Giza were tombs for Egyptian queens and pharaohs more than 4,500 years ago; But how exactly did the Egyptians build such huge pyramids? The Great Pyramid is made of millions of carved stones, each weighing at least two tons.
Even with today’s cranes and other construction equipment, building a pyramid the size of the Khufu Pyramid is a big challenge.
On the other hand, according to astronomical calculations, the pyramids are equal to the stars of the Orion belt. Extraterrestrial theorists often point out that these three pyramids have a better structure than in previous centuries.
Of course, they ignore the fact that architecture has evolved gradually over the centuries; But can it be said that extraterrestrials make the pyramids of Egypt? Not exactly. Scientists are still unsure of how the pyramids of Egypt were built and their speed, but according to the evidence, thousands of people have lifted these stones.
A large circle of rocks, some weighing up to 50 tons, is located in Salisbury, England. This circle, known as Stonehenge, has led many to consider it a solar system model used by extraterrestrials as a landing platform. But how did these large rocks move hundreds of kilometres and get to this point?
One does not know what Stonehenge means, But extraterrestrials are not a good explanation for this structure. Scientists have shown that such a structure can be built using technology 5,000 years ago. Today, these rocks are on par with the solar eclipse, lunar eclipse, and delivery of the years, and show that the builders of Stonehenge stared at the sky with this building.
Teotihuacan means the City of the Gods, an ancient city in Mexico known for its pyramidal temples and astronomical alignments. Build about 2,000 years ago, and the town has raised suspicions that it was built by non-human beings due to the structures’ size, age, and complexity.
Scientists believe that a mix of cultures, including the Maya, Zapotecs and Mixtakes, has made the city, which has hosted more than 100,000 people over the centuries. Teotihuacan was far ahead of its time with evidence such as murals, tools, transportation, and advanced agriculture.
The giant sculptures on Easter Island are precisely the same as the massive structures in other parts of the world in terms of construction pattern and raise the following questions: How were these sculptures made more than 1,000 years ago? How did the Moai (symbols of Easter Island) get to Easter?
Nearly 900 stone human figures are located on the volcanic slopes of the island. The average length of these statues is four meters, and the weight of each reaches 14 tons. There are still more than 400 sculptures in various construction areas, and some of them that complete were waiting to be moved to the desired rest area.
The reason for the hair sculpture is still unknown, But some believe the statues were made for religious or ritual reasons. According to the leading theories of culture, what has happened to the new Rapa civilisation is unclear. If the extraterrestrials were there, they could at least prevent this from happening.
Unidentified flying objects (UFOs)
Unidentified flying object (UFO) or UFO refers to any aerial phenomenon that is not immediately recognisable or justifiable. Most of the UFOs identified were ordinary objects and phenomena.
The term UFO was first coined in the Blue Book project under Edward J. Rapplet; Today, however, UFOs are widely referred to as extraterrestrial spacecraft, which some claim to have witnessed. Many UFOs have been described as flying saucers.
There have been many studies and studies on UFO reports around the world. Research in the United States began in the late 1940s. These studies included the Grudge, Sign and Blue Book projects.
The Blue Book project came to a halt in 1969-1970.
Reports of lights and unidentified bird objects are as old as human history. According to some, these objects can place in a group of phenomena or ordinary things; While a group called ufologists disagree with this claim and believe that there are several hypotheses about these objects.
The UFO debate is still a hot topic in world popular culture today and has become a common topic in science fiction movies, TV series and other media.
Image attributed to UFO in Passaic, New Jersey; This image was taken on July 31, 1952.
History of UFO
Reports of unidentified flying objects go back centuries. These objects were also visible to the naked eye. Of course, most of these claims refer to atmospheric optical phenomena. One such example is the comet Holly, first reported by Chinese astronomers in 240 BC and possibly 467 BC.
They usually considered such comets and phenomena to be supernatural events. Some current UFO researchers have found similarities between some religious symbols in medieval paintings and UFO reports.
Twentieth Century Observations and Beyond
UFO reports they increased dramatically from the twentieth century onwards due to the dramatic advancement of space technology and the rise of various signals. Some of these reports were published due to visual error or atmospheric and weather phenomena and even bird flight, But others remain anonymous, and there is no explanation for them.
UFO reports have grown to such an extent that they have become part of popular culture, and various conspiracy theories have emerged about them. UFO sightings have been reported worldwide in the United States, most notably in Britain, France, and Italy.
UFOs have been reported in many-objective observations around the world. Everyone has jointly written on elliptical objects moving at very high speeds in the sky. One of these high-profile reports is the Roswell UFO accident. In June, or possibly early July 1947, William Brazel discovered a strange object on a Roswell farm in Lincoln State.
He noticed parts of the plane’s shining wreckage made of rubber and tin filaments.
Brazil had never heard of UFOs before. On the other hand, various objective observations were quoted in this regard; For example, on June 24 of that year, a pilot named Kenneth Arnold reported seeing nine unidentified objects moving like a flying saucer on the water near Mount Rainier, Washington. According to Arnold, the speed of these flying objects reached 1930 kilometres per hour, but no plane could fly at this speed.
The Air Force said no new test aircraft or missiles matched those descriptions.
The story became the headline of the news, and the phrase “flying saucer” was born from that time; Arnold, on the other hand, described flying objects as crescent-shaped.
But as public excitement over the narrative escalated, the military tried to downplay the UFO story. The next day, shortly after government scientists arrived at the scene, it reported that the fragments had been scattered by a meteorological balloon hitting the ground, making everyone think the case was closed. Still, speculation grew in the following years, and no definitive conclusions reaching.
Little green men
Little green men are a visual representation of extraterrestrials in the form of tiny humans with green skin and sometimes antennae on their heads. The term is sometimes used to describe mythical creatures that cause problems for aeroplanes or mechanical devices. In addition to green extraterrestrials, species with grey skin have also been reported.
During the heyday of UFO and UFO reports in the 1950s, the term little green men to refer to extraterrestrials peaked. According to one report, in 1955, two Kentucky rural men reported the sighting of silver extraterrestrials up to 1.2 meters in height.
There are many similar reports.
UFO believers consider this incident to be one of the most prominent and documented examples in the history of UFOs. Still, sceptics say such cases are more likely to occur for emotional reasons than not recognising natural phenomena such as meteors and owls. For many people in popular culture, the phrase little green men are reminiscent of extraterrestrial life.
The description of extraterrestrial beings has become part of science fiction culture for decades, But no direct and solid evidence has been found of these creatures.
UFO in Iran
In Iran, as in other countries in recent decades, there have been reports of sightings of unidentified flying objects:
1976: The Tehran UFO Event in 1976 shows a radar report of an unidentified flying object (UFO) in the skies of Tehran. This event became significant due to the electromagnetic interference with a plane close to UFO. The two Jet F-4 interceptors separately lost contact as they approached UFO and were recovered after leaving UFO.
1982: On the summer night of 1982 in Isfahan, thousands of people saw a considerable reflection of an object in the sky.
2003: In August 2003, two tourists, Yvfvhayy white and yellow were spotted near the Caspian Sea.
2004: On April 12-21, 2004, a collection of UFO observations was recorded. Thousands saw uFOs of people. It is not clear whether these observations were UFOs or spy planes, or even the planet Venus. Many images of Iranian UFOs record during this period were labelled anonymous by UFO groups.
2005: A tourist reports seeing a UFO near the tomb of Cyrus.
2007: In an interview with Fars News Agency, eyewitnesses spoke of a brilliant UFO collided with the Barez Mountain in Kerman one Wednesday morning. The object could be a meteorite, officials said. According to another source, the thing was probably a massive fire, with no meteorites. Still, meteors usually appear in the form of fireballs in the sky, and many of them disintegrate due to atmospheric pressure and burn entirely before reaching the earth. In the days before the incident, a similar incident report in Rafsanjan.
Pentagon report on extraterrestrials
Last year, the Pentagon released videos of two unidentified flying objects captured by Navy pilots in 2004 and 2015, respectively. In these videos, UFO-shaped things are seen moving in the air and on the ocean at high speed.
Given the publicity of the videos and the rise of speculation, the Pentagon has decided to publish a clear report on the observations. Finally, the information release was released after months of trying and reviewing more than 144 UFO reports between 2004 and 2021.
According to the Pentagon, only one UFO report revealed the nature of the unidentified object: the giant balloon was being deflated. The report cites other sources such as natural phenomena such as ice crystals and American aircraft, But many of the reported cases were difficult to identify.
Many experts believe that the UFO-induced atmosphere and excitement could fuel these reports, But nothing is unexpected, and extraterrestrials may have visited Earth. Of course, there is no solid evidence for this hypothesis.
The film is known as Gofest, which was recorded in 2015
In October 2017, an unknown object with a strange appearance was seen in the solar system. This object, called the Imamuwa, only appeared in the sky quickly and then continued its journey to distant stars.
This flat, smoky object doubted the minds of many astrophysicists and extraterrestrial experts. Some of them, including Avi Loeb, asked this question:
Should Amuamwa be described as a natural phenomenon that has never been seen before, or should it result from extraterrestrial technology that acts like a solar sail or a very narrow communication plate?
Amuamwa showed strange behaviour. The object showed no signs of gas escaping despite approaching the sun; Instead, its acceleration increased.
But this mass can be the remnant of a non-integrated wandering comet or an extrasolar comet. In July 2019, astronomers concluded that Amuamwa was most likely a natural object. Few considered it to be the result of space technology and have little evidence to support their claim.
According to another hypothesis in March 2021, Imuamua could be part of an extrasolar planet similar to Pluto. At least as far as we know, Amuamwa was the first interstellar visitor to the solar system; But it will not be the last.
Extraterrestrials in popular culture
Years ago, in the late nineteenth century, science fiction writers such as H.W. جی. Wells dealt with such topics as extraterrestrial infiltration and interplanetary warfare.
Interest in extraterrestrials and their influence on popular culture has intensified since the mid-twentieth century, with increasing reports attributed to UFOs. Extraterrestrials have become a hot topic for science fiction novels, movies, and picture books.
Many of these works, such as the Alien Series (1979-1992), Independence Day (1996), and The Martian Invasion (1996), refer to extraterrestrial invasions and hostilities with Earth’s inhabitants; Others, such as ET (1982), referred to extraterrestrial peace with the people of Earth.
The issue of extraterrestrials in the media had a significant impact on public opinion and attracted many fans. To the extent that many men think of extraterrestrials as science fiction movies and series, While this notion is miles away from reality.
Pictured right: Scene from Alien (1979), in which extraterrestrials are hostile creatures. Pictured left: A scene from the 1982 film ET. In this film, extraterrestrials have a friendly nature.
Man has been trying to answer this question for hundreds of years: Are we alone? Many believe that with hundreds of billions of galaxies, stars, and planetary systems, man is unlikely to be the only intelligent, civilised being in the entire universe.
Others believe that it would not be possible to find a living civilisation with advanced technology similar to humans or beyond, at least shortly. Humans would have to wait years to discover such a civilisation.
Scientific hypotheses and conspiracy theories all point to beings beyond the universe or the solar system and raise the possibility that extraterrestrials visited Earth once.
Given the vast scale of space-time, even if a civilisation wanted to conquer the entire galaxy, it would take several million years with Earth-like technology.
The solar system is younger than other star systems in the Milky Way; So if there were inhabitants in the older systems, they should have conquered the earth by now.
However, efforts and questions continue in this area, and institutions like SETI try to find traces of advanced intelligent civilisations by receiving extraterrestrial signals.