Does life exist on other planets?
Does life exist on other planets?
It’s a question anyone who has looked up at the night sky has asked themselves and a team of University of Hawaii at Manoa scientists is proposing a way to answer it.
Their technique involves studying light reflected from planets in other solar systems. If plant life exists there, then certain colors would be almost completely absorbed. By measuring reflected light at different colors, researchers say the signature of leaf biopigments would be revealed, according to a UH-Manoa press release.
Additionally, light that is reflected off plants with vibrant colors oscillates in certain directions.
“Thanks to this peculiarity, this reflected light can be detected remotely by using polarizing filters (similar to Polaroid sunglasses or 3D movie goggles) when viewed at specific angles even if the star is millions of times brighter than the planet,” the release said. “The team found that each biopigment has its own colored footprint in such polarized light.”
That could be differentiated from light reflected off minerals, ocean water and atmosphere, researchers say.
With this technique, scientists could search for life in Alpha Centauri, the closest solar system to our sun, with existing telescopes.
Visiting scientist Svetlana Berdyugina, who is leading the team, said in an email that the search for life there could begin next year. She didn’t say which telescopes might be used.
“It may take some months until we get enough data, if the instruments will perform as we expect,” Berdyugina said, adding this research is at the limit of the instruments’ sensitivity.
Alpha Centauri is home to three stars. Alpha Centauri B, 4.37 light years from Earth, would be the best place to start, UH-Manoa said.
Berdyugina said current statistics suggest that almost every star, if not all, should have Earth-like planets.
Larger telescopes would be needed to use this technique on more distant solar systems, she said.
Scientists announced the discovery of an exoplanet in the system outside the habitable zone in 2012, though some researchers remain skeptical about its presence.
Email Tom Callis at tcallis@hawaiitribune-herald.com.