How close are we, in fact, to detect the alien life? The last major discovery puts into question some essential issues

Until now, science has sought life in other worlds. And never had such tools. There is no question of “if”, but “when”, many believe in the scientific environment.

With the announcement that on a planet called K2-18B there were detected signs of a gas that, on Earth, is produced by simple marine organisms, the signal that we are about to make an epocal discovery, reports the BBC.

“Is there life beyond Earth? This is practically the biggest fundamental question that can exist, and we may be about to find the answer,” says Prof. Nikku Madhusudhan of the Institute of Astronomy of the University of Cambridge, the scientist who led the team that made the discovery related to the planet K2-18B.

But all this opens up more questions. For example, if we find life on another world, how will this change us as a species?

Flying and aliens from science-fiction

For centuries, people have imagined beings who could live in heaven or other worlds. At the beginning of the 20th century, astronomers believed they could see straight lines on the surface of the planet Mars, which fueled speculation that the neighboring planet could host an advanced civilization. It was an idea that inspired science-fiction literature waves, with flying plates and the famous green man.

It was a period when Western governments fed the fear of communism, so visitors in space were often represented as threats, some that brought with them danger, not hope.

But decades later, “the most solid proof so far” regarding the existence of life on another world does not come from Mars or Venus, but from a planet on hundreds of trillion kilometers away.

Major challenge: To know where to look for

Until recently, NASA focused on Mars. But in 1992, with the discovery of the first planets that orbit other stars, the direction changed.

Although astronomers have long suspected the existence of other worlds, there was no clear proof until then. Since then, nearly 6,000 planets from outside our solar system have been discovered.

Many are so-called gaseous giants, like Jupiter and Saturn. Others are either too hot or too cold to support liquid water, an element considered essential for life. At least life as we know it.

But some are in the “Goldilocks area”, the area conducive to life, where the distance from the host star is “just suitable”. And Prof. Madhusudhan believes that there could be thousands of such planets in our galaxy.

Extremely ambitious technologies

As such exoplanets were discovered, scientists have begun to develop tools capable of analyzing the chemical composition of their atmospheres. Their ambition was dizzy, almost defiantly.

The idea was to capture the tiny amount of stellar light that crosses the atmospheres of these distant worlds and analyzes it in search of the chemical fingerprints of the molecules produced by living organisms, the so-called Biosemnite.

And they succeeded. Both terrestrial and spatial telescopes have been equipped with such instruments

NASA's James Webb (JWST) space telescope, which has detected gas on the K2-18B planet, is the strongest telescope ever built. His launch, in 2021, aroused immense enthusiasm. Finally, the search for life seemed out of reach of humanity.

The search for extraterrestrial life will require much more efficient observers

Jwst cannot detect planets as small as ours or who orbite too close to their stars because of the brightness.

That is why NASA is currently building Habitable Worlds Observatory/Housing World Observatory (HWO), whose launch is scheduled for the 2030s.

Such a high precision instrument will be able to detect and analyze the atmospheres of planets similar to Earth, for which it will use a kind of “solar shield” of high technology, which will block the light of the respective star.

Also, Extremely Large Telescope/Extremely large (ELT) part of the European Southern Observatory (ESO) will become operational towards the end of this decade.

According to public data so far, ELT will have the largest mirror ever built, 39 meters in diameter, and will be able to study the planetary atmospheres with unprecedented precision.

More discoveries, more questions

Prof. Madhusudhan hopes to have sufficient data in the next two years to categorically demonstrate that he has detected biosension on K2-18B. But even if he succeeds, he will not follow a wave of global celebration.

Instead, an intense scientific debate will begin. Specifically, could those biological signatures be produced by non-VII processes?

Over time, as the data gathered and the alternative chemistry fails to explain the observed biosemies, the scientific consensus will gradually begin to inclined to the probability of the existence life, says Prof. Catherine Heymans of the University of Edinburgh, Scotland, quoted by the BBC.

“The longer we have on the telescope, the more the image of atmospheric chemistry will become clearer. We will not be able to say for sure it is life. But if we see the same signs in several systems, not just in one case, trust will increase,” she says.

As the Internet appeared through a series of seemingly small progress, but which, over time, changed the world, so it is possible that the moment we realize that we are not alone to be perceived immediately as a revolutionary.

A clearer proof would be the discovery of life in our solar system, through robotic probes equipped with portable laboratories. An eventual extraterrestrial bacterium could be analyzed and even brought to earth, and this would be the first direct proof of the existence of aliens.

Even if simple life is discovered that does not mean complex life is inevitable

Prof. Madhusudhan believes that simple life could be a common one in galaxy. But the evolution from simple life to complex life, and then to intelligence, represents huge and slightly understood.

Dr. Robert Massey, deputy director of the Royal Astronomy Society, agrees that the appearance of smart life is much less likely than the simple one.

“On Earth, the evolution towards multicellular organisms has long lasted. The question is whether there are special conditions that have allowed this here (the size of the planet, the oceans, the land masses), or if these processes could take place anywhere,” says Massey.

Alien life would further reduce the feeling that we are special

He believes that the discovery of simple extraterrestrial life would continue to diminish the feeling that the human species is “special”.

“Oh once we believed the center of the universe. Every discovery has moved us further from that center. The alien life would reduce the feeling that we are special,” Massey believes

Professor Michele Dougherty from Imperial College in London sees, otherwise things: “The discovery of life, even simple, would help us better understand how we evolved. And it would reconnect with something vast. It would make us bigger, no smaller.”

The discovery of extraterrestrial life will not bring fear but hope

“When we look at heaven, we will not only see stars and planets, but a living sky. The social impact will be huge. It will fundamentally change the way we see ourselves and each other. The language, political or geographical borders will dissolve.

“It will be a new step in our evolution,” concluded Prof. Madhusudhan.