Extraterrestrial Footprints: NASA funds alien search through 'technosignatures' like pollution and solar panels
Are we alone in the universe? Over the years, many have pondered over this question. An expedition looking for signs of alien civilizations, which has just received funding from NASA, may provide the answers. The researchers will look for signs of intelligent life or "technosignatures".
Technosignatures are signatures of advanced alien technologies similar to, or perhaps more sophisticated than, what we possess, explains Avi Loeb, Frank B. Baird Jr. Professor of Science at Harvard. "Such signatures might include industrial pollution of atmospheres, city lights, photovoltaic cells (solar panels), megastructures, or swarms of satellites," they added.
Until now, astronomers have devoted resources to finding simple forms of life, known as “biosignatures”. They have surveyed distant lands for chemicals that could signal microbial presence.
Besides, alien hunters have struggled to figure out their targets. "Which stars do you point your telescope at and look for signals?" said Adam Frank, a professor of physics and astronomy at the University of Rochester, and the primary recipient of the grant. "Now we know where to look. We have thousands of exoplanets, including planets in the habitable zone, where life can form. The game has changed."
The new project runs on the premise that civilizations produce energy. Frank says, “There are only so many forms of energy in the universe. Aliens are not magic.”
Finding chemicals and solar panels on distant lands
The light absorbed by a chemical could reveal its identity. On Earth, researchers use this method to detect methane, oxygen, and artificial gases such as chlorofluorocarbons (CFCs) in the atmosphere. Similarly, this group is aiming to search for CFCs, which could indicate an active industrial civilization.
"We have come a long way toward understanding how we might detect life on other worlds from the gases present in those worlds’ atmospheres,” says Jason Wright from Pennsylvania State UniversityWright, who is also a part of the team.
The other clue is to look for any indication of the use of solar energy. On Earth, humans harness the sun for energy. So the team speculates that other alien civilizations could also be doing the same. If a population is using solar panels, the light reflected from their home planet could have a unique sign. In their project, the researchers will determine the signatures of large-scale planetary solar energy collection.
If extraterrestrial life exists in Proxima b, which orbits the Earth's nearest star Proxima Centauri, they need to depend on technology. More so because the exoplanet is tidally locked, meaning one part of the planet has permanent days and the other has permanent nights. "If a civilization wants to illuminate or warm up the night side, they would place photovoltaic cells on the dayside and transfer the electric power gained to the night side."
The team will put together a database that could help experts look for alien life. “Our job is to say, ‘this wavelength band is where you might see certain types of pollutants, this wavelength band is where you would see sunlight reflected off solar panels,” Frank says. “This way astronomers observing a distant exoplanet will know where and what to look for if they’re searching for technosignatures.