The fact we are alive and pondering a vast Universe from spaceship Earth raises a number of fascinating questions. Astrophysicist are now asking why “here” and why “now”. What is the chance of life emerging around a star like the Sun, about 12-13 billion years after our Universe was born?
A recent work looked at the past, and set a lower bound on the probability that one or more technological species have evolved anywhere and at any time in the history of the observable Universe (Frank 2016). The authors conclude that is very likely that humanity is not the first technological intelligence that has evolved, so far, in the Universe. “Yes, There have been aliens” seems to be the conclusion of this work, although the Fermi paradox seems to point out that either intelligence is a very rare avenue of life and/or alien civilizations do not last very long, or that aliens like to play hide-and-seek with us.