▲Fermi asked how it could be possible to not have any evidence of other intelligent life in the universe if the probability of its existence was so high.

▲This theory proposes that life has existed elsewhere in the universe but that it has never had the same opportunity to grow and evolve as it has on Earth.

▲As human beings, we are curious about our existence and the world around us. As we discover more and more about the universe we live in, we increasingly feel the need to question whether or not we are alone in it.

▲We have been listening for radio frequencies for less than a century, so we still would not have received signals from any intelligent life located farther than 100 light years from Earth.

▲Italian-American physicist Enrico Fermi posited his now-famous paradox in the early 20th century.

▲Life could hypothetically exist in these deep oceans but, even if evolved enough to be intelligent, it would face enormous obstacles trying to reach the surface of its own planet, let alone be able to send out signals.

▲Another explanation for the lack of evidence of extraterrestrial life is known as the zoo hypothesis.

▲Giant radio antennas and telescopes are used to send out and listen for potential radio transmissions.

▲Scientists have discovered oceans trapped under thick layers of ice on some of Saturn's and Jupiter's moons.

▲Unstable and shifting planetary environments could cause life to die off before having the chance to evolve any sort of advanced intelligence.

▲Many projects have existed for decades in an attempt to find other intelligent life in the universe, but we have yet to make contact with anything (or anyone) else.

▲These issues include not having the proper technology to interpret the transmissions sent out by other intelligent life, simply not receiving the signals because they are not directed at us, and being located too far away, meaning the signals have yet to reach us.

▲One theory that attempts to explain why we have not achieved contact with other intelligent life is known as the Great Filter.

▲This theory refers to an event that prevents a civilization from reaching the level of technological advancement necessary for interstellar travel or communication.

▲However, there are many possible problems with using radio frequencies to determine whether intelligent life exists beyond Earth.

▲Not to be ruled out is the theory that aliens are already on Earth and living among us.

▲Other methods include looking for bright flashes of light that could indicate laser beams.

▲The event in question may involve a cataclysmic disaster that wipes out existing life or could just represent the cosmic limits of technological advancement.

▲Organizations including NASA, the European Space Agency, and the Search for Extraterrestrial Intelligence (SETI) have invested in projects to search the stars for signs of life.

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He points out that we have barely explored our own galactic neighborhood, let alone our galaxy, and that if we hope to hear from extraterrestrial life, we may need to wait another 1,500 years, give or take.

▲Another theory postulates that due to the relatively young age of our Solar System and Earth, aliens have already visited our corner of the galaxy and we've just missed them.

▲Astrophysics student and researcher at Cornell University, Evan Solomonides, wrote a paper outlining his research on the probability of extraterrestrial life, in which he suggested that we just need to be patient.

▲Our galaxy alone is estimated to contain between 100 and 400 billion stars, with many of them potentially surrounded by planets.

▲The hypothesis proposes that extraterrestrial life forms are aware of our existence but are intentionally avoiding contact in order to study us from a distance and not disturb our "primitive" society.

▲Scientists have reported that there could potentially be billions of planets orbiting the habitable zone around their stars in the Milky Way galaxy, meaning that they could contain the conditions necessary for life to exist.

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Technological advancements have allowed us to explore our solar system and galaxy in ways we never thought possible. The more we learn about the universe around us, the more we want to know if there are other beings out there doing the same thing. Other forms of life must exist in the endless expanse of space, so why haven't we found them?

Well, we're still a long way away, but a recent discovery by scientists in Canada reaffirms the theory that there is life out there. Astronomers using a powerful radio telescope have picked up mysterious radio signals from a far-away galaxy. The signal comes in the form of an intense burst of radio waves. Such signals have been detected before, but only lasted for a matter of milliseconds. This one, however, lasted for a full three seconds and came in a clear periodic pattern. Astrophysicist Daniele Michilli commented that the pattern sounded like a heartbeat. It is the longest radio signal ever detected from outer space. While the source is uncertain, researchers can confirm that it comes from another galaxy several billion light-years from earth.

The following gallery outlines some of the existing theories that attempt to explain why we haven't yet established real contact with potential extraterrestrial life. Check it out!

From science fiction to reality: the evolving search for extraterrestrial life

Where are all the aliens?

11/10/24 por StarsInsider

LIFESTYLE Aliens

The following gallery outlines some of the existing theories that attempt to explain why we haven't yet established real contact with potential extraterrestrial life. Check it out!