According to a study published in The Astrophysical Journal claimed that there are 36 intelligent alien civilizations in the Milky Way. They might not be blue in colour or have a solar panel on their heads or might not own a UFO but are definitely capable of communicating with others. 

Though its conclusions are speculative, the study incorporates new metrics and approaches in approximating how many alien societies within the Milky Way are capable of interstellar messaging (a group known as Communicating Extraterrestrial Intelligent civilizations, or CETI). 

Experts say the work not only offers insights into the chances of life beyond Earth but could shed light on our own future and place in the cosmos. 

Christopher Conselice, a professor of astrophysics at the University of Nottingham and a co-author of the research said:

It is extremely important and exciting because for the first time we really have an estimate for this number of active intelligent, communicating civilisations that we potentially could contact and find out there is other life in the universe – something that has been a question for thousands of years and is still not answered.

In 1961 the astronomer Frank Drake proposed the Drake equation, which sets out seven factors that would help find out and estimate the number of intelligent civilisations out there. 

These factors ranged from the average number of stars that form every year in the galaxy to the timespan over which a civilisation would be expected to be sending out detectable signals. Now Conselice and colleagues refined the equation with new data and assumptions to come up with their estimates. Conselice said:

Basically, we made the assumption that intelligent life would form on other Earth-like planets like it has on Earth, so within a few billion years life would automatically form as a natural part of evolution. 

He further added that, while it is a speculative theory, he believes alien life would have similarities in appearance to life on Earth.  

Under the strictest set of assumptions where life forms between 4.5bn and 5.5bn years after star formation on Earth, there are likely between four and 211 civilisations in the Milky Way today capable of communicating with others, with 36 the most likely figure. 

But Conselice noted that this figure is conservative, not least as it is based on how long our own civilisation has been sending out signals into space, a period of just 100 years so far. 

The team adds that our civilisation would need to survive at least another 6,120 years for two-way communication. Conselice said:

They would be quite far away. 17,000 light years is our calculation for the closest one. If we do find things closer, then that would be a good indication that the lifespan of communicating civilisations is much longer than a hundred or a few hundred years, that an intelligent civilisation can last for thousands or millions of years. The more we find nearby, the better it looks for the long-term survival of our own civilisation.

Are the aliens trying to contact us?