Extra terrestrial life in the universe is calculated using the “Drake equation” N = R* • fp • ne • fl • fi • fc • L, even at that time the result was non zero, considering that since then we have found a multitude of exo-planets this “non zero” number must have increased dramatically.
National Geographic quotes “More Than 1,000 Potential New Planets Found“, I am not sure how many were known of in 1961, but I do know that the scientific community were surprised just a few years ago at how many they had already found compared to how many they expected to find.
It was not that long ago that the human race knew that the Earth was flat and that we were the only intelligent species in the universe, since that time we have moved on a long way, (except for the Flat Earth Society and a few others). we know that the Earth orbits the Sun, that our solar system is part of the Milky-way Galaxy and we are only one of many solar systems in the Milky Way Galaxy.
I did read something somewhere that someone has revised the Drake Equation to bring it upto date, unfortunately I cannot find that reference right now.
I for one, cannot believe that we are alone in the universe, considering the multitude of stars in just our galaxy, which is currently quoted as being 100–400 billion. Even on the conservative side that is still an astronomical (no pun intended) amount just in our galaxy. The amount of galaxies in our universe is estimated at anything from 100 billion to 500 billion! Taking that amount and multiplying it by the number of stars in any given galaxy gives you a number that would make anyone’s brain hurt.
What would be the current estimation of extra terrestrial life ?