NOTTINGHAM: A new study revealed that there could be a minimum of 36 active civilizations in Milky Way galaxy. The study was published in 'The Astrophysical Journal'.

The authors wrote in their study that, "Astronomer and astrophysicist Frank Drake developed an equation to calculate the number of Communicating Extra-Terrestrial Intelligent (CETI) civilizations in the Galaxy. However, many of its terms are not known and other methods must be used to calculate the likely number of communicating civilizations."

The scientists at the University of Nottingham developed their own approach. Christopher Conselice, Professor of Astrophysics at the university of Nottingham asserted that the main difference between their calculation and previous ones based on the Drake equation is that they make simple assumptions about how life has been developed.

Christopher said that, "There should be at least a few dozen active civilizations in our Galaxy under the assumption that it takes 5 billion years for intelligent life to form on other planets, as on Earth."

He further added that, "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."

Tom Westby, an assistant professor in the University of Nottingham's faculty of engineering said that, "The two Astrobiological Copernican limits are that intelligent life forms in less than 5 billion years, or after about 5 billion years like that of Earth. A technological civilization was formed after 4.5 billion years." He stated that their new study will simplify these assumptions using new data and thereby gives a solid estimate of the number of civilizations in our Galaxy.

The number of civilizations depends on how long they have been sending out signals of their existence into space, such as radio transmissions from satellites, television, etc.