Search of 100,000 galaxies finds no sign of alien life

Researchers are finding no obvious signs of life after digging through thousands of galaxy images in search of advanced civilizations.

Amanda Kooser
Freelance writer Amanda C. Kooser covers gadgets and tech news with a twist for CNET. When not wallowing in weird gear and iPad apps for cats, she can be found tinkering with her 1956 DeSoto.
Amanda Kooser
2 min read

Great Galaxy
The WISE telescope's view of mid-infrared emission from the Great Galaxy in Andromeda. Picasa, NASA/JPL-Caltech/WISE Team

I find the concept of humanity being alone in the universe to be much more frightening than the concept of finding an alien race that might want to eat us or import us for display in galactic zoos. A new study from Penn State University might just keep me up an night. Researchers scoured 100,000 galaxies and came up empty on finding any obvious signs of advanced civilizations.

The research team studied data from NASA's Wide-Field Infrared Survey Explorer (WISE) space telescope. "Whether an advanced spacefaring civilization uses the large amounts of energy from its galaxy's stars to power computers, space flight, communication or something we can't yet imagine, fundamental thermodynamics tells us that this energy must be radiated away as heat in the mid-infrared wavelengths," said Jason T. Wright, assistant professor of astronomy and astrophysics at the Center for Exoplanets and Habitable Worlds at Penn State University.

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The scientists scoured the WISE data for signs of too much mid-infrared radiation. Out of 100,000 galaxy images, only 50 appeared to have unusually high levels of the radiation, but there were no obvious signs of activity that could be attributed to advanced civilizations. Follow-up studies of those 50 galaxies should be able to determine if the radiation levels are the result of natural processes.

The team's findings are published in The Astrophysical Journal Supplement Series.

As disappointing as this research may sound for people eager for signs of extraterrestrial intelligent life, there are a few points to remember. It could be there are some primitive civilizations out there that aren't generating mid-infrared emissions. "Either they don't exist, or they don't yet use enough energy for us to recognize them," said Wright.

Another cause for hope is that 100,000 galaxies is a mere fingernail clipping of the universe. Scientists suspect the number of galaxies out there is at least one hundred billion. The study is just the beginning of a much larger quest.

"As we look more carefully at the light from these galaxies, we should be able to push our sensitivity to alien technology down to much lower levels, and to better distinguish heat resulting from natural astronomical sources from heat produced by advanced technologies," said Wright.

We can look at the study as a combination of good news and bad news. Good news: we didn't find a Predator civilization out there. Bad news: we also didn't find E.T. or Wookiees. It's also certain we won't stop looking after this minor science setback.