Recently, Gliese 581g was declared 100 percent certain to have life. Now the question has been raised, is it intelligent life?
Gliese 591g: 100 percent certainty of life
Professor Steven Vogt of the Carnegie Institution in Washington who declared the new-found planet to be within the elusive "habitable zone"--a zone that Vogt estimates encompasses at least 10 to 20 percent of all planets in the universe--stunned the world after a press conference where the professor went on record contending that "Personally, given the ubiquity and propensity of life to flourish wherever it can, I would say, my own personal feeling is that the chances of life on this planet are 100 percent."
As Earth's sun is what is known as a third generation star--meaning other stars developed billions of years before the sun--the prospect arises that life developed on other worlds uncounted eons before the solar system was created. The idea is both simultaneously mind-boggling and sobering.
Frank Drake doubtful
Possibility of life in our solar system
Astronomers and exobiologists have argued for some time that if life is discovered on other planets within our own solar system that it would likely be rife throughout the universe. Although some in the past have argued that life is rare--and intelligent life rarer still--the consensus of experts has gradually turned a collective eye more favorably upon the hypothesis that life is ubiquitous and a natural evolution of the universe.
Recent findings of running water on Mars and the high presence of methane gas--strongly considered more biological than geological in origin--lend weight to the belief that Mars had life in the past and may have life presently.
Titan, the large satellite orbiting Saturn, also hints at the possibility of life.
Original article here.