Scientific Theories on the Search for Extraterrestrial Life

There are some important international scientific efforts in the search for extraterrestrial life.

These include; The search for extrasolar planets, Listening to extraterrestrial signals that indicate intelligence, Robotic exploration of the Solar System, among many other experiments.

Scientists search for extraterrestrial life in three main ways:

Direct search, that is, the observation of microbial life or of any kind in the celestial bodies that humanity comes to visit.

Indirect detection, or the detection of distinctive features or marks of life on celestial bodies through advanced telescopes.

Listening to artificial signals, which would allow the detection of true extraterrestrial civilizations that emit electromagnetic radiation as a by-product of their technological advancement.

Because the UFO Phenomenon for the moment remains essentially outside the scope of science (due to the lack of data, and therefore the possibility of experimenting and refuting the hypotheses), there is no formal discipline that studies extraterrestrial life, nor some academic curriculum that trains experts on the subject.

Those who have approached the subject in a scientific way are generally experts in various areas, who out of personal interest have developed hypotheses about the possibilities of life on other worlds, and have shared their points of view through some medium.

However, an enormous amount of serious work and publications has emerged on the subject, so that one can speak of a quasi-science dedicated to studying and theorizing about this phenomenon, despite the absence of evidence.

The proto-science that studies extraterrestrial life is called exobiology or astrobiology, and it essentially speculates on the limits within which, according to our scientific knowledge, life could exist.

The term extraterrestrial life refers to the type of life that may exist outside of planet Earth and that did not originate from it. Such life can vary from simple prokaryotes to beings with civilizations much more advanced than humanity.

A growing portion of the scientific community is inclined to consider that some form of extraterrestrial life may exist in places where conditions are conducive, although it is generally considered that such life probably exists only in basic forms.

An alternative hypothesis is panspermia, which suggests that life could arise in one place and then spread among other habitable planets.

It is speculated with extraterrestrial life forms ranging from bacteria, which is the majority position, to other more evolved life forms, which may have developed intelligence of some kind. The discipline that studies the viability and possible characteristics of extraterrestrial life is called exobiology.

Due to the lack of evidence for or against, any scientific approach to the subject always takes the form of guesswork and estimates.

Researchers at the University of Oxford suggest that, far from being monstrous beings as science fiction shows, aliens may have more in common with us than we thought.

The team shows for the first time how the theory of evolution can be used to find out what extraterrestrial life looks like and can develop.

In this way, they believe that aliens are potentially shaped by the same processes and mechanisms that shaped humans, such as natural selection. And like us, they evolve to be more prepared and stronger over time.

Some scientists, such as University of Pennsylvania astrophysicist Jason Wright, a fellow at the Center for Exoplanets and Habitable Worlds, believe that a technological species could have existed in our planetary system in an era before humanity emerged on Earth.

In his opinion, the most obvious reason for the disappearance of a civilization before us would be "a cataclysm, either a natural event, such as an extinct asteroid impact, or self-inflicted, such as a global climate catastrophe."

In that case, that species could have produced artifacts or other technological signals that would have survived to this day. Looking for those artifacts instead of microbes would be, for Wright, a potential way to solve once and for all the great question of Astrobiology.

Héctor Socas Navarro, a researcher at the Instituto de Astrofísica de Canarias (IAC), proposes to look for traces of possible technological civilizations by looking at what are called Clarke's exobelts. The term was coined by the writer and inventor Arthur C. Clarke to refer to the band of geostationary satellites that exist around the Earth. And, according to the researcher, their presence could be captured on other planets if satellites obscured the light of distant stars. The interesting thing is that he proposes to look for a tech marker that is based on a real technology, on something mundane that we ourselves do.

Two articles recently published in the Monthly Notices of the Royal Astronomical Society analyze what would happen in parallel universes with higher proportions of dark energy than ours.

Through massive computer simulations, researchers have created universes with different initial parameters and thus have discovered that the conditions necessary for the appearance of galaxies and places where life can appear are not as exclusive as is often thought, which has important implications for multiverse theory.

The authors have calculated that universes with up to 300 times more dark energy than ours would be compatible with the appearance of galaxies and, therefore, of life.

A team made up of 33 researchers from the world's most prestigious universities recently published unusual research in which they argued that life did not originate on Earth.

In the study they say that complete organisms, both plant and animal, have arrived on our planet, and are currently arriving, and not just organic molecules, as was believed until now. Organisms that can give rise to new evolutionary lines, to explosions of life.

Terrestrial Planet Finder - A space telescope project dedicated to photographing extrasolar planets.

Due to the recently acquired ability to detect extrasolar planets or exoplanets orbiting stars other than our Sun, a strong interest has been generated among the astronomical community in discovering worlds comparable in size and properties to Earth; planets that are just beginning to be detected. There is also a strong interest in the possibility of actually observing such worlds using much more sophisticated telescopes than are currently available.

Listen to Artificial Signals

It has been theorized that any technological society will be transmitting information: electromagnetic radiation generated by humans is detectable in a radius of more than 50 light years from Earth, and they are constantly expanding.

The SETI project (Search for Extraterrestrial Intelligence) or "Search for Extraterrestrial Intelligence", analyzes the data collected by large radio telescopes and analyzes them looking for artificial patterns using supercomputers, as well as a large distributed computing project in the world; SETI @ home.

To date, however, only the Wow! has been noteworthy in this search.

Over time there have also been a series of initiatives in the opposite direction: not looking for the signal of a possible extraterrestrial intelligence, but informing potential listening civilizations of our presence. The first was the so-called Arecibo Message, launched in 1974 in the direction of the M13 star cluster. On board the probes Pioneer 10 (towards the star Aldebaran) and Pioneer 11 (towards the constellation Aquila) are two messages (see Pioneer Badge) destined for a possible extraterrestrial civilization that could intercept the probes. The same occurs in the case of the Voyager Gold Record, in the Voyager 1 (in the direction of the constellation Ophiuchus) and Voyager 2 (in the direction of the star Ross 248). 

More recently, in 2008, a team of Ukrainian scientists sent messages in the direction of the Gliese 876.7 system. On February 5 of the same year at 0:00 UTC NASA broadcast the song "Across the universe" by the British band The Beatles on direction to the Polaris star which is 431 light years from Earth, using a 70m antenna at DSN's outside Madrid in order to celebrate NASA's 50th anniversary, the 45th anniversary of the Deep Spacial Network ( DSN) and the song's 40th anniversary.

The Fermi paradox, proposed by the Italian Nobel Prize winner in Physics of the same name, raises the big question: If intelligent life has arisen on our planet and there are billions of stars in the galaxy, the same could have happened elsewhere as well. .

Speculation about possible extraterrestrial life forms, especially intelligent ones, as well as their possible civilizations and relationships with human beings have been and are also covered by science fiction and ufology.