Do Aliens Exist? Science, UFOs, and the Jewish View, Part I

Yuval asks: “I’ve often come across pictures and video clips of flying saucers. Is there any scientific evidence for the existence of aliens? What does Judaism say about their existence?”

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Hello Yuval, and thank you for your question.

At present, there is no scientific proof that intelligent extraterrestrial beings exist on other planets. In fact, there is not even evidence for the existence of any form of life including plants, animals and bacteria, anywhere in the universe outside of Earth.

What Science Currently Indicates

Scientific findings actually make the existence of extraterrestrial civilizations more difficult to assume.

Radio signals travel through space at the speed of light. Because modern technological societies produce countless radio signals through satellites, communications systems, and other technologies, such signals spread into space and do not simply disappear. This means that any technologically advanced civilization would likely leave detectable traces in space.

For this reason, astronomers established the famous SETI project (Search for Extraterrestrial Intelligence) decades ago. Its goal was to detect intelligent signals from other star systems. The project used a giant radio telescope with a diameter of 305 meters and spent years listening to signals from hundreds of stars across more than a billion radio frequencies.

Despite billions of dollars invested and decades of effort, the project has not detected even a single confirmed intelligent signal.

Space Exploration and the Search for Life

In addition to radio searches, satellites and space probes have explored our solar system, photographing planets, moons, and asteroids. Any unusual object in space would immediately attract global attention.

Yet no spacecraft has ever found evidence of even microscopic life beyond Earth. According to current observations of the universe, Earth appears to be the only place known to host life.

NASA, the American space agency, has never announced the discovery of extraterrestrial beings, and all missions launched so far have failed to detect any biological life elsewhere.

The Physical Limits of Interstellar Travel

Another major difficulty for the idea of visiting alien spacecraft lies in the laws of physics. According to modern physics, no material object can travel faster than the speed of light. Any spacecraft attempting such speeds would break apart before reaching them.

This means that traveling between distant star systems would take millions of years. Such enormous travel times make the idea of aliens visiting Earth extremely unlikely.

Science-fiction concepts such as “wormholes” are sometimes proposed as solutions, but these ideas remain speculative and currently have no practical scientific basis.

Therefore, if communication with extraterrestrial civilizations were ever possible, it would most likely occur through radio signals traveling at the speed of light, rather than through physical visits.

The Uniqueness of Our Solar System

Another scientific point worth considering is the unusual structure of our solar system.

Professor Abraham Loeb, former chair of the astronomy department at Harvard University, explained that the escape velocity required to leave our solar system is about 42 kilometers per second. This relatively low escape velocity makes it possible — at least in principle, for spacecraft to leave the solar system.

According to his calculations, many other star systems have much higher escape velocities, which might make it extremely difficult for a civilization to develop spacecraft capable of leaving its own solar system.

Research suggests an additional challenge. Professor Michael Hippke from the Sonneberg Observatory in Germany argues that many planets outside our solar system are so massive that escaping their gravitational pull could be extremely difficult.

If this is correct, even intelligent beings living on those planets might never be able to leave their own worlds.

What About Flying Saucers?

Many people point to photographs or videos of unidentified flying objects as evidence for extraterrestrial visitors.

However, modern computer graphics (CGI), video editing, and digital effects make it extremely difficult to distinguish between genuine images and fabricated ones, especially when the footage is of low quality, as is often the case with alleged UFO videos.

Serious scientific investigations of such materials have found that most are either hoaxes, misidentifications, or unreliable recordings.

Even if some sightings cannot immediately be explained, they do not prove the existence of extraterrestrial visitors.

A Simpler Explanation

A far more straightforward explanation for many unidentified aerial objects, is human technology.

Human beings already launch satellites, weather balloons, advanced fighter jets, stealth aircraft, and sophisticated military helicopters. At night, these machines can appear as mysterious moving lights in the sky.

In recent years, the development of drones has advanced rapidly. Many drones have disc-like shapes and are capable of hovering in one place for long periods before moving quickly in controlled directions.

Therefore, if “flying saucers” are observed, the most reasonable explanation may simply be that a government or military organization has developed a new type of experimental aircraft.

In a future discussion, we will examine surprising evidence that governments — particularly the United States, have experimented with aircraft resembling flying saucers, and we will explore what Judaism says about the possibility of extraterrestrial life.