From: Pennsylvania State University
Posted: Wednesday, June 24, 2020
A team of researchers including Penn State Professor of Astronomy and Astrophysics Jason Wright has been awarded a grant from NASA to look for detectable signs of technology used by past or present extraterrestrial civilizations. This marks the first time NASA has awarded an external grant to look for "technosignatures" other than radio signals. The grant is also the first to support work at the new Penn State Extraterrestrial Intelligence (PSETI) Center, which is dedicated to advancing the search for technosignatures.
Since the first discovery of a planet orbiting a solar-type star outside our solar system in 1995, scientists have identified more than 4000 exoplanets, including some Earth-like planets that may have the potential to harbor life. In order to detect if planets are harboring life, however, scientists must first determine what features indicate that life is or once was present.
"Astronomers have spent the last decades trying to understand what detectable traces of biological life, called 'biosignatures,' might exist in the universe," said Wright. "We've recently started asking what technological signatures an extraterrestrial civilization might leave behind that could be seen from Earth."
The grant will allow the research team to produce the first entries in an online technosignature library. The project is led by Adam Frank from the University of Rochester, and other team members include 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.
"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 research is based on the principle that any technology that an alien civilization uses is going to be based on physics and chemistry. This means researchers can use what they've learned in labs on Earth to guide their thinking about what may have happened elsewhere in the universe.
The researchers will begin the project by looking at two possible technosignatures that might indicate technological activity on another planet:
Solar panels. 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.
Pollutants. "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 catalogue the signatures of chemicals, such as CFCs, that indicate the presence of an industrial civilization.
This research will also support the mission of the PSETI center to create a world-class SETI research program at Penn State, to train the next generation of SETI researchers with a graduate curriculum, and establish a worldwide SETI community.
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