There are many people who strongly believe that aliens are real and they are living somewhere far from the blue planet, Earth. But a new scientific study suggested that such civilizations destroyed themselves through progress.

NASA Jet Propulsion Laboratory and California Institute of Technology researchers have surmised in a study that the galaxy might be home to alien civilizations that destroyed themselves through technological advancements that eventually lead to destruction and biological degeneration.

According to the paper, "A Statistical Estimation of the Occurrence of Extraterrestrial Intelligence in the Milky Way Galaxy", any intelligent alien life that lived in the Milky Way before humans did likely already killed itself off.

Milky Way Galaxy
Alien life in Milky Way Pikrepo

Dead Alien Civilization

The researchers behind this study, Xiang Cai, Jonathan H. Jiang, Kristen A. Fahy, and Yuk L. Yung, explained in the paper that "if intelligent life is likely to destroy themselves, it is not surprising that there is little or no intelligent life elsewhere".

If people are wondering why humans, the most intelligent living being on planet Earth and on the solar system, might still be alive, it is because the species are billions of years behind these now-extinct alien civilizations. The intelligent species or aliens probably noticed life form around eight billion years after the formation of the Milky Way, whereas humans did not reach until 13.5 billion years after the creation. This means the humans are almost over five billion years behind.

According to Jiang, the NASA Jet Propulsion Laboratory astrophysicist, since Carl Sagan's time, there has been lots of research on alien life, especially when the Hubble Space Telescope and Kepler Space Telescope were created. "We have lots of knowledge about the densities in the Milky Way galaxy and star formation rates and exoplanet formation...and the occurrence rate of supernova explosions. We actually know some of the numbers," he added.

Center of the Milky Way Galaxy
Photo of the Milky Way's center taken by the Spitzer Space Telescope NASA, JPL-Caltech, Susan Stolovy SSC/Caltech et al.

The numbers are actually related to the mystery variables that the American astronomer and the planetary scientist Segan referred to in his Cosmos miniseries in which he discussed the Drake equation. This formula proposed by American astrophysicist Frank Drake estimates N, the number of transmitting societies in the Milky Way galaxy. It is actually the equation that may give the scientists an idea about how many alien societies exist and are detectable.

Because of the scientific limitations at that time, Drake and Sagan included variables that could not be identified more precisely. But now Jiang and the team of scientists have learned about some of those numbers which Drake and Segan failed to identify. The paper says when and where life is most likely to flourish in the Milky Way and it identifies the most important factor affecting its prevalence that is intelligent creatures' tendency toward self-annihilation.

Understanding the factors helped the team of scientists believe that advanced alien civilizations did exist at one point in the galaxy, but they likely destroyed themselves by way of progress. However, according to some scientific theories, there might be 36 extraterrestrial races among the stars.

Earlier in 2018, scientists claimed that the galaxy used to be the home to aliens but it was the effect of climate change that vanished all the life forms, as per a report from Forbes. In the recently released paper, the researchers said, "The simulated age distributions also suggest that most of the intelligent life in our galaxy are young, thus making observation or detection difficult."

They also found that even if the galaxy reached its civilizational peak over five billion years ago, most of the civilizations that were around that time have likely self-annihilated. However, the paper has been submitted to a journal for publication and it is currently awaiting peer review.