In a new paper published in the Astrophysical Journal, Dr. Ravi Kopparapu of NASA’s Goddard Space Flight Center and colleagues assessed the potential detectability of solar panels made of silicon on an Earth-like exoplanet as a potential technosignature.
“The search for extraterrestrial life has primarily focused on detecting biosignatures, which are remote observations of atmospheric or ground-based spectral features that indicate signs of life on an exoplanet,” Dr. Kopparapu and co-authors said.
“More recently, technosignatures referring to any observational manifestations of extraterrestrial technology that could be detected or inferred through astronomical searches has received increased attention.”
“While the search for extraterrestrial intelligence through radio observations has been popular for decades, recent studies have proposed alternate searches for technosignatures in the ultraviolet to mid-infrared part of the spectrum.”
The astronomers assume that extraterrestrials would build solar panels out of silicon because it’s relatively abundant compared to other elements used in solar power, such as germanium, gallium, or arsenic.
Also, silicon is good at converting the light emitted by Sun-like stars into electricity and it’s cost-effective to mine and manufacture into solar cells.
The researchers also assume that a hypothetical extraterrestrial civilization would rely exclusively on solar energy.
However, if other sources of energy are used, such as nuclear fusion, it would reduce the silicon technosignature, making the civilization even harder to detect.
They further assume that the civilization’s population stabilizes at some point. If this doesn’t happen for whatever reason, perhaps they will be driven to expand ever-father into deep space.
For the study, the scientists used computer models and NASA satellite data to simulate an Earth-like planet with varying levels of silicon solar panel coverage.
They then modeled an…
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