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Do aliens exist: what scientists think
Do aliens exist: what scientists think
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There are many rumors surrounding the Pentagon's UFO report. Are there aliens, and can you establish contact with them? The popular scientific publication asked this question to five experts: astrophysicist, astrobiologists, planetary scientist and space technology specialist. The four agreed.

Numerous rumors about the Pentagon report on unidentified aerial targets began to circulate long before the publication of its unclassified part at the end of June.

Presumably, the document contains a comprehensive description of what the US government knows about unidentified aerial phenomena - or unidentified flying objects (UFOs), as they are most commonly called by the people.

Not so long ago, The New York Times published material based, according to journalists, on the material of a review of the reported attributions of high-ranking officials familiar with the content of the report. These individuals remained anonymous. According to newspaper sources, the report does not describe a clear connection between more than a hundred incidents involving unidentified flying objects recorded in the past two decades and the alleged visit to Earth by aliens.

According to the sources of The New York Times, we still have no reason to interpret unidentified objects in the sky as evidence of the existence of aliens. But does this mean that they really do not exist? And if they are anywhere in the universe, can we find them? Or maybe they are so different from us that we are simply not able to detect them in the sense in which it would matter to us?

We asked five experts.

Four out of five of our experts believe that aliens exist

Jonti Horner, astrobiologist

I believe the answer is an unequivocal yes. But, in my opinion, a much more important question: are they close enough to us for us to be able to detect them?

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The cosmos is incredibly large. Over the past few decades, we've learned that almost every star in space has planets. Our Milky Way galaxy has up to 400 billion stars. If each of them had five planets, there would be two trillion planets in our galaxy alone.

And we know that there are more galaxies in space than there are planets in the Milky Way. In other words, there are plenty of places to stay. And with such a great variety, I find it difficult to believe that the Earth is the only planet on which there is life, including intelligent, technologically advanced.

But will we ever discover such extraterrestrial life? Complex issue. Imagine that for every billion stars there is one that has a planet where a technologically advanced civilization was able to develop, capable of shouting out its existence into space.

Well, this will mean that there are 400 stars in our galaxy with technologically advanced civilizations. But our galaxy is huge - 100,000 light-years from end to end. This is so much that, on average, stars with civilizations will be about 10,000 light-years apart. This is too far for us to pick up signals (at least today), unless they turn out to be much more powerful than we can send ourselves!

So while I believe aliens exist, it is extremely difficult to find evidence of this.

Steven Tingay, astrophysicist

Yes. But this is, of course, a bold statement. So let's be clear on what exactly this is about.

I believe that the term "alien" encompasses all forms of life in our earthly sense, living in any place other than the Earth.However, there is currently no full consensus on the definition of life. This is a very complex concept. But if we found something like bacteria anywhere outside Earth, I would classify it as alien life.

There are hundreds of billions of galaxies in the universe, and in each of them there are billions and billions of stars. Most stars have at least one planet. These systems are formed from a rich mixture of elements, including those believed to be essential for the origin and maintenance of life. Thus, it is difficult to believe that a special combination of conditions that resulted in the emergence of life on Earth has developed only in our country, but not on trillions of other planets in the universe.

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However, it is not yet known what kind of life it is: something like bacteria or a breathtaking "technologically advanced civilization" with which we could establish communication. Significant efforts are now being made to search for alien civilizations that can use technologies similar to ours, such as powerful radio telescopes that transmit radio wave messages from distant planetary systems.

And, of course, it may well turn out that our definition of life is too narrow, and aliens - wherever they are - play by completely different rules.

Helen Maynard-Casely, planetary scientist

I am of the opinion that it is only a matter of time before we discover something akin to life beyond Earth. Recently, we increasingly find places in our solar system that are potentially favorable for life as we know it. Take, for example, the subglacial oceans on Europa and Ganymede (the two large moons of Jupiter): there the temperature is right, there is water, and the necessary minerals.

But, again, this is reasoning through the prism of our earthly experience. Of course, alien life can be very different from ours.

This is why I am so glad that we continue to study Saturn's moon Titan. There are so many interesting molecules found on the surface of Titan, as well as active meteorological conditions conducive to their spread - and this is also in our own solar system. And we know that there are other planetary systems in our galaxy.

Considering all of the above, it seems more or less inevitable that someday we will find habitats for some active bioorganisms. Will they be able to say hello to us? Now that's another question.

Rebecca Allen, Space Technology Expert

Yes, but they probably don't look like us.

It is estimated that there are more than 100 billion planets in our galaxy alone (about 6 billion could potentially be similar to Earth). Therefore, the likelihood that extraterrestrial life exists is practically confirmed.

However, when we hear the word "alien", some kind of humanoid life forms usually come to mind. But even on Earth, the prevailing forms of life are much older, smaller and more resilient than we are. Of course, I'm talking about microorganisms. These organisms challenge our scientific expectations because they live in places where life seems to have nothing to do - for example, in the ash around volcanic vents. I bet that alien life exists in the form of these "extremophiles".

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In fact, NASA recently sent a company of tiny tardigrades (also called "water bears") to astronauts on the International Space Station to study their behavior in extreme environments. With the key ingredients for life found in our solar system, it seems likely that Earth's most resilient organisms could be found throughout the galaxy.

But what about a more advanced life? The point is that space is huge. Through the work of NASA's space observatory, we have learned that finding other worlds is difficult, let alone knowing if they are similar to Earth.Remember that it took billions of years for life to develop on Earth, and you will understand that the chances of finding aliens similar to us are very small.

But hope is alive, and scientists continue to use advanced radio telescopes to look in the sky for new unusual signals that could be mistaken for an attempt at communication.

Martin Van-Kranendonk, astrobiologist

The simple answer to this question is no.

If we rely solely on empirical data and assume that the question concerns any form of life outside the Earth, not related to human activities, then the answer, as far as we know, should be “no”.

But, of course, our knowledge on this matter is limited - we have not examined every corner of the universe for signs of life, and we do not even know what life in another chemical system might be. Plus, even here on Earth, there is no universally accepted definition of life based on carbon.

So, perhaps a more detailed answer would sound like this: we do not know. In fact, it is possible that we will never be able to answer this question at all. But, of course, a lot of work is being done now to try and do that.

Perhaps one day we will find out if we have neighbors in outer space. Or are we really all alone? Or maybe not.

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