“Astronomers have spent the last decades trying to understand what detectable traces of biological life, called ‘biosignatures,’ might exist in the universe,” said Penn State astrophysicist Jason Wright about NASA’s funding a new effort to look for “technosignatures” other than radio signals based on the principle that alien technology is going to be based on physics and chemistry. “We’ve recently started asking what technological signatures an extraterrestrial civilization might leave behind that could be seen from Earth.”
But could this new NASA-funded project be like searching or the evolutionary needle in the galactic haystack? We humans have only recently entered the epoch we are now calling “the Anthropocene,” which will appear as nothing compared with the mountainous stacks of rock that make up the other epochs, according to mass-extinction authority, Peter Brannen.
The Anthropocene Illusion
“Humans are congratulating themselves,” Brannen observes, “on an unearned geological legacy before we’ve proved ourselves capable of escaping the next century with our lives. And, besides, most of our proudest creations—whole cities and manufactured landscapes—will be destroyed by the ceaseless destruction of tectonics and erosion…many of the synthetic markers proposed to delineate the Anthropocene will not survive the insults of deep time. Human history, though environmentally cataclysmic and sedimentologically interesting, is not usefully described in the terms of a geological epoch on par with a yawning span of time like the Early Cretaceous, an epoch that lasted 600,000 times longer than this newly minted one.”
There have been many planet Earths
“There have been many planet Earths” says astrophysicist Adam Frank who talks about climate change from an astro-biological lens. If Earth’s geological history, a span almost 10 times as long as all of recorded human history, can easily wear the Himalayas flat, what chance will an alien “San Francisco” or “New York” have of surviving a new geological epoch of our own making, the Anthropocene that started maybe 400 years ago, when carbon dioxide dipped by a few parts per million in the atmosphere. Or perhaps, as a panel of scientists voted earlier this year, the epoch started as recently as 75 years ago, when atomic weapons began to dust the planet with an evanescence of strange radioisotopes.
So NASA’s new Technosignatures mission will have to hit the exact number in the alien evolution roulette wheel. How many of the current number of 4100 exoplanets will be in their own detectable Anthropocene Epoch? Or will their civilizations have gone extinct, or be in their version of the Age of Dinosaurs, which lasted for 450 million years?
The NASA team of researchers led by Frank includes Jacob-Haqq Misra from the Blue Marble Space Institute of Science, Avi Loeb from Harvard University, and Manasvi Lingam of the Florida Institute of Technology, who will look for the first time for detectable signs of technology used by past or present extraterrestrial civilizations. The grant is also the first to support work at the new Penn State Extraterrestrial Intelligence Center, which is dedicated to advancing the search for technosignatures.
The grant will allow the research team to produce the first entries in an online technosignature library. “We hope to identify the spectral signatures — measurements of the wavelengths of light that are reflected from or absorbed by an exoplanet — that might be associated with different kinds of technosignatures,” said Wright. “Cataloging these signatures into a library will provide an important comparative tool and will help give astronomers an idea of what to look for when studying exoplanets.”
The researchers will begin the project by looking at two possible technosignatures that might indicate technological activity on another planet:
Stars are one of the most powerful energy generators in the universe. On Earth, we harness energy from our star, the sun, so “using solar energy would be a pretty natural thing for other civilizations to do,” said Frank. If a civilization uses a lot of solar panels, the light that is reflected from the planet would have a certain spectral signature indicating the presence of those solar collectors. The researchers will determine the spectral signatures of large-scale planetary solar energy collection.
“We have come a long way toward understanding how we might detect life on other world from the gases present in those worlds’ atmospheres,” said Wright. On Earth, we are able to detect chemicals in our atmosphere by the light the chemicals absorb. Some examples of these chemicals include methane, oxygen, and artificial gases such as the chloroflourocarbons (CFCs) we once used as refrigerants. Biosignature studies focus on chemicals like methane, which simple life will produce. Frank and his colleagues will catalog the signatures of chemicals, such as CFCs, that indicate the presence of an industrial civilization.
Andrew Siemion, director of the U of California Berkeley SETI Research Center, wrote The Daily Galaxy in an email that “I suspect there are other intelligent civilizations in the Milky Way – we just need to look!” But, asks Frank, will they, or have they, survived their Anthropocene bottleneck?