Study On Possible Intelligent Life In Milky Way Sheds Light On Humanity's Future

Researchers of a new study estimated there could be over 30 intelligent civilizations in the Milky Way, which may even reveal important information about the future of humanity.

The Milky Way is home to about 400 billion stars, but not all of them can host life-supporting planets such as the Earth. Researchers have tried to determine how many intelligent life forms could be present on other planets in the Milky Way, with previous estimates ranging from zero to billions.

In a new study published in The Astrophysical Journal, researchers approached the question of the existence of other intelligent life forms using a new method they called the Astrobiological Copernican Principle.

Under this approach, the assumption is that life forms on other planets just like they do on Earth, in that it takes about five billion years for intelligent life to develop. On Earth, for instance, it took 4.5 billion years for a technological civilization capable of communicating to develop. Today, humanity's "technological civilization" is just about 100 years old.

The approach also assumed the stars hosting intelligent life-supporting planets are rich in metals, just like the sun, and took into account the likelihood of them to host Earth-like planets in their habitable zones.

In other words, the researchers' estimates were based on the assumption that the existence of life on Earth is not unique, as life on other planets may have developed in a similar way.

Given these factors, the researchers estimated there should be about 36 active civilizations in the Milky Way. However, they are quite far away, with the average distance between these civilizations being 17,000 light-years away. This means, even if they do exist, communicating with them would be very difficult unless they survive for long.

The assumption is that these civilizations are also making their presence known, just like humanity is doing with signals from satellites, radios and the like. In humanity's case, we have only been sending out signals for about a hundred years, so communicating with another intelligent civilization may still be a very long way away.

In fact, the researchers estimated the communicating civilization on Earth would have to survive for 6,120 years beyond the advent of long-range radio technology, which was just 100 years ago, before achieving a two-way communication with extra-terrestrial intelligence.

Even under more relaxed assumptions of the Weak Copernican case wherein there would be at least 928 civilizations closer to the Earth communicating in the galaxy today -- much more than the 36 suggested in the new study -- it would still take 700 years.

The researchers also noted how their study also sheds light on a possible future for human civilization.

"If we find that intelligent life is common then this would reveal that our civilization could exist for much longer than a few hundred years, alternatively if we find that there are no active civilizations in our Galaxy it is a bad sign for our own long-term existence," study lead Professor Christopher Conselice said in a news release from the University of Nottingham. "By searching for extraterrestrial intelligent life -- even if we find nothing -- we are discovering our own future and fate."

Simply put, if humans eventually find other civilizations, it could mean civilizations like our own could last for much longer. Not finding another civilization could suggest a shorter lifespan for our own, or perhaps show life on Earth is really more unique and existed from a much more random process than the study established.