I. The Most Distant Known Star
According to the most recent observations by the Hubble Space Telescope and the James Webb Space Telescope, the most distant star whose light we have detected is called Earendel. It is located approximately 12.9 billion light-years from Earth. The light we receive today left the star when the universe was only about 900 million years old after the Big Bang. It was detected thanks to a phenomenon known as gravitational lensing, which amplifies its light as it passes through a cluster of galaxies. Hubble first identified it in 2022 as the most distant star ever observed. Webb confirmed and studied its characteristics in 2023, verifying its extreme distance.
Why is it so special? Normally, at such distances we can only see entire galaxies, not individual stars. Earendel is visible because the curvature of space-time magnifies its light thousands of times.
II. Estimated Size of the Observable Universe
Current studies indicate that the observable universe—that is, the portion of the universe from which light has had time to reach us since the Big Bang—has a radius of approximately 46.5 billion light-years. Its diameter is about 93 billion light-years. This may seem strange because the universe is about 13.8 billion years old, but the expansion of space makes current distances much greater than the time light has traveled.
As for the size of the entire universe, we do not know. It could be much larger than the observable universe, and some even believe it may be infinite. The reason is that we can only measure what lies within our cosmic horizon; beyond that, light simply has not had enough time to reach us.
III. How Many Stars Are There in the Observable Universe?
Recent studies estimate that there are approximately 1 × 10²⁴ stars in the observable universe. This is one septillion stars (American numbering system), a 1 followed by 24 zeros. This figure comes from combining approximately 2 trillion galaxies in the observable universe, each containing between 100 billion and 400 billion stars on average.
IV. How Many Planets Are There in the Observable Universe?
There is no direct count, but we can estimate it using what we know about the Milky Way. In our galaxy, virtually every star has at least one planet, and many have several. If we apply that proportion to the total number of stars, a reasonable estimate is about 1 × 10²⁴ to 5 × 10²⁴ planets (between one and five septillion planets). Although there is no exact figure in the sources consulted, this extrapolation is based on the star-planet relationship observed by missions such as Kepler.
What Does “Intelligence” Really Mean in Biology? Intelligence is defined as the ability of an organism to process information, learn, adapt, and solve problems.
There are different types of intelligence:
i) instinctive intelligence (insects and fish),
ii) simple learning intelligence (dogs and cats),
iii) complex problem-solving intelligence (dolphins and crows),
iv) symbolic intelligence (humans).
Human intelligence is the only one that combines:
a) complex language,
b) abstract thinking,
c) long-term planning,
d) cumulative culture,
e) technology.
But there are levels. Let us first consider how many living beings there are. Since they cannot be counted one by one, scientists use indirect methods, considering:
i) total biomass by organism type,
ii) average density by volume (soil, oceans, air),
iii) ecological models,
iv) microbiology and environmental genetics studies.
Most living beings are microorganisms, not animals. We know that there are trillions upon trillions of living beings on Earth. Insects alone are estimated to number about 10²¹ individuals (one sextillion). If we add bacteria, plants, fungi, animals, and other organisms, the total exceeds 10³⁰ organisms.
Since there are about 8 billion humans (8 × 10⁹), humans represent approximately 0.0000000000000000008% of all living beings—essentially zero.
V. How Many Intelligent Beings Are There in the Observable Universe?
We do not know whether intelligent life exists outside Earth. If we assume that only humans are intelligent (the only case we know with certainty), then 100% of known intelligent beings are us. We represent an insignificant fraction of all living organisms.
What Percentage Do We Represent as Intelligent Beings in the Universe?
Let us first consider what “intelligence” means in biology and how human intelligence compares with that of other animals.
Intelligence is not a single thing. There are different types.
Capabilities in which humans are unique:
a) complex symbolic language,
b) advanced abstract thought,
c) science and technology,
d) cumulative culture,
e) mathematics and formal logic.
Animals with notable intelligence:
a) dolphins: complex communication and advanced cooperation,
b) elephants: exceptional memory, empathy, and mourning behavior,
c) crows and parrots: problem-solving abilities and tool use,
d) great apes: basic sign language and planning.
However, no other animal demonstrates:
a) technological civilization,
b) writing,
c) advanced mathematics,
d) complex symbolic art.
Therefore, although many forms of intelligence exist, human intelligence is the only one that has reached a cognitive level capable of transforming the planet.
Since Homo sapiens is the only confirmed intelligent species among living beings, we currently represent 100% of known intelligent beings. This does not mean we are the only intelligent beings in the universe, only that we have confirmed only our own existence.
What Is the Probability That Other Intelligent Life Exists?
We do not know.
Factors suggesting that it might exist include:
a) approximately 10²⁴ stars and 10²⁴–10²⁵ planets,
b) many celestial bodies located in habitable zones,
c) the commonness of life’s chemistry (carbon, water, amino acids),
d) life appeared on Earth relatively quickly after the planet formed.
Factors suggesting it may not be common include:
a) we have not detected technological signals,
b) we do not observe megastructures or large-scale engineering,
c) complex life took 3.5 billion years to appear,
d) technological intelligence appears to have arisen only once, as far as we know.
This is known as the Fermi Paradox: “If the universe is full of planets, where is everybody?”
What Is the Mathematical Probability of Intelligent Life?
The mathematical probability of intelligent life is often estimated using the Drake Equation. Although it does not provide an exact number, it helps estimate how many technological civilizations might exist in the galaxy.
The equation considers factors such as:
i) the number of stars formed each year,
ii) the percentage that have planets,
iii) the number of habitable planets,
iv) the probability that life arises,
v) the probability that life evolves intelligence,
vi) the duration of a technological civilization.
Depending on the values used, the result can range from hundreds of civilizations to none at all. The equation itself is not flawed; what we lack are the actual values.
The Fermi Paradox is the contradiction between the high probability that intelligent civilizations exist in the universe and the fact that we have no evidence of them. Enrico Fermi formulated it in 1950 with his famous question: “Where is everybody?”
What exactly does it consist of? Astronomers know that:
i) the galaxy contains hundreds of billions of stars,
ii) many are older than the Sun,
iii) most have planets,
iv) some of those planets may be habitable.
By pure statistics, there should be many advanced civilizations. Yet we see nothing: no signals, no visits, no technological traces. That is the paradox. The universe appears full of opportunities for life, but we detect no civilizations—not even one. The Drake Equation suggests that contact should not be so rare, yet we still have no signals. More than twenty hypotheses have been proposed, ranging from the possibility that we are the first civilization to the possibility that civilizations destroy themselves, or that they are here but we fail to recognize them.
Some time ago I wrote the above, but lately there have been new developments. What has recently been revealed regarding extraterrestrials?
Recently there have been many “revelations” and declassifications concerning UFOs/UAPs (Unidentified Anomalous Phenomena), but it is important to distinguish among three things:
1. What is confirmed.
2. What remains unexplained.
3. What consists of claims without conclusive evidence.
What Has Officially Been Revealed?
The governments of the United States and other countries have acknowledged that objects or phenomena detected by pilots, radar systems, and military sensors have sometimes been impossible to identify immediately. This is no longer considered a conspiracy theory; it is official.
Several important developments occurred during 2025 and 2026:
• U.S. Congressional hearings involving military personnel and whistleblowers discussing unusual encounters with UAPs.
• New declassifications of Pentagon files related to videos, photographs, and military reports.
• Additional scientific studies of UAPs, including academic research seeking to analyze them using physical data and sensors.
• The subject has evolved from being considered ridiculous to becoming a matter of aviation safety and scientific analysis.
The Most Famous Case: David Grusch
One of the major catalysts was former intelligence officer David Grusch, who testified under oath that the United States allegedly possesses secret programs dedicated to recovering “non-human” technology.
His claims include:
i) recovered craft,
ii) materials of “non-human origin,”
iii) government concealment.
However, to date:
i) he has not publicly presented verifiable physical evidence,
ii) no independent evidence has conclusively confirmed these claims.
Is There Real Evidence of Extraterrestrials?
As of today, there is NO conclusive public evidence that extraterrestrial life has visited Earth.
There are, however:
i) unusual videos,
ii) military testimonies,
iii) radar-detected objects,
iv) cases lacking a definitive explanation.
But “unexplained” does not automatically mean “alien.”
Many experts believe that some cases may result from:
i) advanced drones,
ii) sensor errors,
iii) atmospheric phenomena,
iv) secret military technology,
v) misinterpretations.
What Is New in 2025–2026?
Recent developments receiving significant attention include:
• Declassification of UAP files. The U.S. administration has released additional documents and videos concerning unidentified aerial phenomena.
• Increased reports. Civilian organizations such as NUFORC reported a substantial increase in sightings during 2025.
• More serious scientific studies. Researchers are using:
i) infrared cameras,
ii) multispectral sensors,
iii) artificial intelligence,
iv) statistical analysis
to study UAPs rigorously.
• Documentaries and public pressure. The documentary “The Age of Disclosure” reignited worldwide debate by featuring testimony from former officials and military personnel.
The Most Honest Conclusion Today
The current situation is as follows:
• There are real aerial phenomena that remain unexplained.
• Governments and scientists now acknowledge that they deserve investigation.
• Whistleblowers have made extraordinary claims.
• There is still no definitive public proof of extraterrestrial visitors.
The major change is not that extraterrestrials have been confirmed, but that governments no longer automatically dismiss the phenomenon and now investigate it openly.
[1] 1 day = 86,400 s; 1 year = 365 days = 31,536,000 s; 1 light-year = 31,536,000 s × 300,000 km/s = 9.46 × 10¹² km.
19. Curiosities: i)The most distant known star, ii)The size of the known universe, iii)How many stars are there in the observable universe? iv)How many intelligent beings are there in the observable universe, and what percentage do we represent? v)What is the mathematical probability of intelligent life existing? vi)What has been revealed recently about the existence of extraterrestrials?
