Fluorescent glow may reveal hidden life in the cosmos
Phys.org - Tue 13 Aug 22:40 GMT

Astronomers have uncovered a new way of searching for life in the cosmos. Harsh ultraviolet radiation flares from red suns, once thought to destroy surface life on planets, might help uncover hidden biospheres. Their radiation could trigger a protective glow …

  Harsh ultraviolet radiation flares from red suns, once thought to destroy surface life on planets, might help uncover hidden biospheres.

  Their radiation could trigger a protective glow from life on exoplanets called biofluorescence, according to new Cornell University research.

  Maybe such life forms can exist on other worlds too, leaving us a telltale sign to spot them," said co-author Lisa Kaltenegger, associate professor of astronomy and director of the Carl Sagan Institute Astronomers generally agree that a large fraction of exoplanets—planets beyond our solar system—reside in the habitable zone of M-type stars, the most plentiful kinds of stars in the universe.

  M-type stars frequently flare, and when those ultraviolet flares strike their planets, biofluorescence could paint these worlds in beautiful colors.

  Credit: Cornell University "Such biofluorescence could expose hidden biospheres on new worlds through their temporary glow, when a flare from a star hits the planet," said Kaltenegger.

  The astronomers used emission characteristics of common coral fluorescent pigments from Earth to create model spectra and colors for planets orbiting active M stars to mimic the strength of the signal and whether it could be detected for life.

  In 2016, astronomers found a rocky exoplanet named Proxima b—a potentially habitable world orbiting the active M star Proxima Centauri, Earth's closest star beyond the sun—that might qualify as a target.