Are there aliens? American astronomers have hit the nail on the head

In 2020, the Pentagon took the rare step of releasing a video of the UFO and said it would investigate the source of the incident.

Believe it or not, although we've never found any direct or indirect evidence of aliens, many people still believe in them. Surveys show that at least half of Americans believe that aliens have been to Earth (not just whether they exist, mind you, but have actually visited), and that belief is growing.

So, in the minds of scientists, do aliens exist or not?

Chris Impey, an astronomy professor at the University of Arizona who has written extensively about the search for extraterrestrial life and teaches courses on the subject, offers his take on the UFO incident.

Unidentified Flying Object. First of all, Unidentified Flying Object. In other words, anything flying or floating in the sky, as long as we have not confirmed its nature, can be called a UFO. Therefore, UFO is not directly related to aliens, and you don't need to see the three letters to associate it with aliens.

Admittedly, there are some UFO incidents that are worth noting. Since the 1940s, the U.S. Air Force has investigated some truly bizarre UFO incidents. But as it turns out, the vast majority of UFO incidents end up as Close to Science style explanations of natural events, and the rest just hang in the balance, with no extraterrestrial clues.

According to statistics, about half of all UFO incidents are actually meteors or celestial bodies. These phenomena are common to astronomers, and the public, limited by the scope of knowledge, can easily mistake them for Ufos. Impey also made it clear that he had never seen a UFO, and that what might be considered a UFO by ordinary people was nothing more than normal to him. In addition to these astronomical phenomena, many Ufos are actually man-made objects.

For example, in the famous Roswell incident of 1947, there were claims of a UFO crash, and even rumors that three aliens were among them, but the United States Air Force investigation concluded that it was just a military hot air balloon that crashed.

Even so, people's enthusiasm for Ufos has not abated, but become more and more crazy. Even for Roswell, there have been all kinds of bizarre rumors.

IMPEY also found that a large proportion of the world's reported UFO incidents occur in the United States and are particularly concentrated near the US-Canada border and the US-Mexico border. He also found it unreasonable that Asia and Africa, which make up the majority of the world's population, rarely report these bizarre UFO incidents.

Among other details, he found that a large proportion of the people who reported UFO sightings were walking their dogs or smoking cigarettes. IMPEY's analysis suggests this is probably because such people spend more time outside the home. In addition, UFO sightings tend to occur in the early evening, especially on Fridays.

No matter when or by whom they are found, as we have just said, these Ufos are ultimately proven to be natural phenomena. Even James Oberg, a former NASA employee, went back decades to reports of Ufos and clues, and finally found a natural explanation.

Because of this, we rarely see scientists doing research on whether aliens have come to Earth or UFO incidents. Such news usually comes from so-called civilian science. By contrast, scientists have focused more on actually looking for life in the universe. In a prestigious journal like Nature, we're also going to see more articles about habitable planets than we're going to see articles about Area 51 that are purely fanciful.

So, since scientists don't pay much attention to whether aliens are here on Earth, what do they think about life in the universe?

Generally, scientists think about this problem in terms of the Drake equation, which was developed by the American astronomer Frank Drake in 1960. The Drake equation involves many parameters, but it can be roughly divided into two parts: the first is the number of planets in the galaxy that have the conditions to harbor life, and the second is the probability that such planets will actually harbor intelligent life like humans. That is, although the probability of life appearing is low, if there are enough planets, then we won't be alone in the universe.

To date, scientists have found more than 4,000 exoplanets in the universe, and the number has been doubling every two years in recent years. And there are many more potential and yet to be confirmed exoplanets. Among these exoplanets are many candidates in the habitable zone that scientists believe could harbor life.

Gliese581D is currently considered one of the most promising exoplanets for supporting life, and it's only about 20.5 light-years away. That led scientists to speculate that there could be 300 million planets in the galaxy with similar habitable environments. That's a sizable base, so some scientists are confident about extraterrestrial life.

So as scientists' confidence in extraterrestrial life has grown, their focus has shifted from "do they exist?" to "where are they?" in what has become known as the Fermi Paradox. And scientists have come up with a variety of theories, each of which makes good sense.

However, they do not believe that extraterrestrial life has actually visited Earth, at least in recent decades, the so-called evidence is not reliable, especially the UFO incidents. It's not that they don't believe in aliens, it's just that the evidence doesn't convince them.

Impey also pointed out that he does not simply think that people who believe in Ufos are aliens are crazy, as there are still a number of UFO incidents that remain unexplained and there is a real possibility of extraterrestrial intelligence.

But he also said that a survey of young people showed that those who were so obsessed with Ufos that they indiscriminately linked many events to extraterrestrial intelligence were more likely to have anxiety tendencies and even paranoia. So he also advises those who tout extraterrestrials for no reason to think about whether they might have a problem.

Finally, he concludes with a quote from famed science writer Carl Sagan: "It's a good thing to have an open mind, but don't be too open or your brain will explode."