With thanks to Prager University

from the Huffingtom Post: Posted: 04/15/2015 9:06 am EDT

Scientists Scan 100,000 Galaxies And See No Signs Of Alien Life. What Do E.T. Hunters Say Now?

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 Earthwithin 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.