According to a new study, Earth and humanity are not alone with an estimated 30 alien civilizations out there in the Milky Way Galaxy.

One assumption is that these Earth-like conditions and similar patterns produce flora and fauna in an article by Independent.

An implication of the study is the possible existence of civilizations that are active in the Milky Way galaxy.

Christopher Conselice from the University of Nottingham stated that in our spot in the galaxy,there's a good chance of a few dozen extant and active civilizations now.

It took approximately 5 billion years to develop life just like on Earth, which has similarities with Earth-based carbon life forms or not.

Enter the 'Astrobiological Copernican Limit'

Instead of evolution that is localized on Earth, it is on an unprecedented mind-boggling cosmic scale. A new way to frame and contrast the two, the Astrobiological Copernican limits have two forms according to the study, reported in Science Daily.

One is defined as the weak limit, which suggests that any planetary flora and fauna will exist after 5 billion years on a cosmic value. Another is the Strong limit that says all flora and fauna will be existing from 4.5 to 5 billion years ago.

One catch of the new study is a certain condition for the planet to have life or it is a dead world. If the developing planet is metal-rich, just like Earth then life may take hold on a dust ball.

Also read: Scientists Might Have Witnessed the Birth of a New Planet for the First Time

The source of metal is the sun which birthed the evolution of humans and all life on Earth.

It is suggested that a study in 2012 stated a specific "minimum stellar metallicity" that is the basis of the formation of Earth-like planets.

Assuming that "minimum stellar metallicity" is what is required for life to flourish on alien worlds, then it can help consider other planets in the Milky Way.

If there are civilizations out in the cosmos, they should be sending any broadcasts or find me signals into the stellar void.

What kind of signals are other civilizations sending, or ET Phone Home?

The current state of our civilization is capable of radio transmissions coming from satellites and television. Based on current technology and sending out these frequency emissions into deep space for about a hundred years, giving about 36 same as us intelligent civilizations right now, mentioned in Forbes.

Stellar distances are great and just saying "hello" is a challenge. It will be 17,000 light-years to the nearest civilized star system with distance and time as the wall that separates all.

Professor Conselice added the new study gives ideas if there are others and how much time to exist, or when the Earth dies. Said study is published in The Astrophysical Journal.

One of these 30 alien civilizations might be in Proxima B near the Proxima Centauri star, about 4.4 light-years, and might be one of these worlds like Earth.

Related article: Astronomer Believes That Life in Universe Exists Other Than Humans on Earth