What if researchers, in the search for life on distant planets, could find alien organisms by their light? That's the idea proposed in a paper published this week by two scientists at Cornell University — that light, produced by the extraterrestrial equivalent of coral, could be detected using powerful future telescopes. The scientists based their suggestion on these observations: Many other solar systems contain young and angry M stars, which, when they flare, drench exoplanets in ultraviolet light. Here on Earth, that light can damage cells. Plants and coral have adaptations to defend themselves from these UV rays. Coral proteins, for instance, can absorb harmful light and spit it out at safer wavelengths, in what the authors of the study call "photoprotective biofluorescence." (That's unlike bioluminescence, which is a chemical reaction that produces light, such as a firefly's twinkle.) In theory, alien organisms living in a shallow ocean may re-emit light after a solar flare near their planet. "Maybe such life-forms can exist on other worlds too, leaving us a telltale sign to spot them," said study author and astronomy professor Lisa Kaltenegger, in a statement. Astronomers already measure distant light emitted from exoplanets. These fluorescent signatures can reveal the kinds of gases within a planet's atmosphere. And, as long as an exoplanet's cloud cover wasn't too thick, biofluorescence from living things could be detectable too, per the study authors' calculations. "This is a completely novel way to search for life in the universe. Just imagine an alien world glowing softly in a powerful telescope," said co-author Jack O'Malley-James, in a statement. Still, this remains a theoretical proposal. Current telescopes aren't strong enough to glimpse biological light. But in a few decades? Perhaps, the authors say. |
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