Scientists Scan 100,000 Galaxies And See No Signs Of Alien Life

Excerpt from huffingtonpost.com

Just how realistic is it to believe that humans will someday find evidence of extraterrestrial life?

NASA’s chief scientist recently predicted that we’d find signs of life beyond Earth within a decade or so, but a new study by researchers at Penn State — one of the most exhaustive of its type — isn’t very encouraging.


After surveying tens of thousands of galaxies surrounding our own Milky

Way galaxy, the scientists turned up no sign of advanced alien

civilizations.

“These galaxies are billions of years old, which should have been plenty of time for them to have been filled with alien civilizations, if they exist,”

Dr. Jason T. Wright, an assistant professor of astronomy and

astrophysics at the university’s Center for Exoplanets and Habitable

Worlds and one of the researchers, said in a written statement. “Either

they don’t exist, or they don’t yet use enough energy for us to

recognize them.”

Turning up the heat. For the research, Wright and his colleagues analyzed a vast catalog of observations made in 2010 by NASA’s Wide-field Infrared Survey Explorer (WISE) space telescope. The team looked at the heat emitted by the 100,000 “most promising” candidates of the all-sky catalog’s nearly 100 million entries.

“The

idea behind our research is that, if an entire galaxy had been

colonized by an advanced spacefaring civilization, the energy produced

by that civilization’s technologies would be detectable in mid-infrared

wavelengths — exactly the radiation that the WISE satellite was

designed to detect for other astronomical purposes,” Wright said in the

statement.

The hypothesis that advanced civilizations could be recognized by their waste heat was first put forth by renowned theoretical physicist Freeman Dyson in 1960, according to Space.com.

Time to give it up?

Despite his negative findings, Wright said his study, published April

15 in the Astrophysical Journal Supplement Series, was “just the

beginning,” and that further research may yet turn up evidence of alien

technology.

And other experts involved in the search for

extraterrestrial intelligence (SETI) told The Huffington Post that

they’re far from discouraged.

Dr. Avi Loeb, a theoretical

physicist at the Harvard-Smithsonian Center for Astrophysics in

Cambridge, Mass., told HuffPost Science in an email that it’s possible

alien civilizations are hard to detect because they use much less energy

than Dyson proposed.
“The limits reported in this study rule out

the most extreme environmental impact possible for an extraterrestrial

civilization that harvests a significant fraction of the starlight in

its host galaxy,” he said. “For comparison, our civilization processes

only a thousandth of a trillionth of the energy output of the sun. Less

visible civilizations are much more likely to exist, both in terms of

the technological feasibility of energy harvesting as well as in terms

of their energy needs.”

Legendary astronomer Dr. Jill Tarter,

the former director of the Center for SETI Research in Mountain View,

Calif. and the astronomer on whom Jodie Foster’s character in the 1997

film “Contact” was loosely based, agreed that efforts to find

extraterrestrial life should continine.

“It’s absolutely not time

to stop,” she told The Huffington Post in an email. “It’s time to

improve the sensitivity and specificity of these searches to be able to

discriminate between signals produced by Mother Nature and those

produced by engineers.”

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Scientists Scan 100,000 Galaxies And See No Signs Of Alien Life