December 8, 2010

Stacking Evidence Shows Likelihood Of Alien Life

New discoveries point to it being more likely that humans are not the only inhabitants in the universe.

"The evidence is just getting stronger and stronger," Carl Pilcher, director of NASA's Astrobiology Institute, which studies the origins, evolution and possibilities of life in the universe, told The Associated Press (AP). "I think anybody looking at this evidence is going to say, 'There's got to be life out there.'"

Scientists have an equation that calculates the odds of civilized life on another planet.  However, that equation mostly includes factors that are pure guesswork on less-than-astronomical factors, such as the likelihood of the evolution of intelligence and how long civilizations last.  The calculations hinge on two basic factors:  How many places out there can support life?  And how hard is it for life to take root?

The Associated Press interviewed 10 scientists who all agreed that with more evidence pouring in, it is becoming more and more likely that there is alien life in the universe.

Seth Shostak, senior astronomer at the SETI Institute in California, told AP that "All of these have gone in the direction of encouraging life out there and they didn't have to."

Shostak said that given the growing evidence, people who believe Earth is the only place harboring life is essentially like believing in miracles.  "And astronomers tend not to believe in miracles."

However, despite the mounting evidence, scientists have yet to have prove that life exists outside of Earth.

NASA astrobiologist Chris McKay told AP that "There are real things we can point to and show that being optimistic about life elsewhere is not silly."

Donald Brownlee, an astronomer at the University of Washington, is less optimistic about finding life outside of this planet. 

He told AP that if it does exists then is likely microbes that cannot be seen easily from great distances.  He also said that the different geologic and atmospheric forces on planets may keep life from evolving into something complex or intelligent.

Despite the lack of proof, Shostak bets a cup of coffee for everyone in the audience at his lectures that scientists will find proof of alien life by about 2026.  He said the odds have never been more in his favor.

Image Courtesy NASA/JPL-Caltech/S. Stolovy (SSC/Caltech)


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