An analytical breakthrough that could significantly improve our chances of finding intelligent life in our galaxy has been discovered by a team at The University of Manchester. In new research published in Monthly Notices of the Royal Astronomical Society, the researchers demonstrate a reanalysis of existing data that represents a new milestone in the Search for Extra-terrestrial Intelligence (SETI).
The analysis, say, researchers, can only locate intelligent and technically advanced civilizations that use radio waves as a form of communication — they could not, for example, detect “simple” life or non-technical civilizations. The team is made up of Masters student Bart Wlodarczyk-Sroka and his advisor Professor Michael Garrett at The University of Manchester in the UK, collaborating with Dr. Andrew Siemion, Director of the Breakthrough Listen Initiative, have placed the best limits ever on the prevalence of artificial radio transmitters, dubbed techno-signatures, in the Milky Way.
Combing through the catalog produced by the European Space Agency’s (ESA) Gaia spacecraft, which measured the distances to over a billion stars, the researchers recalculated limits on the prevalence of transmitters around additional stars within the radio telescope’s fields of view. By selecting stars out to much larger distances (up to about 33,000 light-years) than the original sample of nearby stars, they were able to expand the number of stars studied from 1,327 to 288,315.
“Knowing the locations and distances to these additional sources,” he says, “greatly improves our ability to constrain the prevalence of extra-terrestrial intelligence in our own galaxy and beyond. We expect future SETI surveys to also make good use of this approach”.
“Our results help to put meaningful limits on the prevalence of transmitters comparable to what we ourselves can build using twenty first century technology. We now know that fewer than one in 1600 stars closer than about 330 light years host transmitters just a few times more powerful than the strongest radar we have here on Earth. Inhabited worlds with much more powerful transmitters than we can currently produce must be rarer still.”
The sheer number of stars studied enabled Wlodarczyk-Sroka to place some of the most stringent limits to date on the prevalence of powerful radio transmitters in this region of our Galaxy. In addition, for the first time, the team has been able to do this as a function of stellar type — the extended sample includes not only a wide range of main-sequence stars, but also numerous giant stars and white dwarfs.