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NASA and NOAA satellites measure vegetation on Earth from space to produce images like this showing plant life from April 2012 to April 2013.
Credit: NASA / NOAA
The rise of plants was crucial to turning the Earth from an aqueous rock into a world in which humans could flourish – and our house might not be the only planet where this process took place.
Scientists have therefore decided to investigate the Earth's vegetative history in order to examine how it could guide our search for habitable exoplanets. The result is a new document that focuses on what scientists call the red edge of vegetation, which simply means that the Earth is reflecting a relatively large amount of near-infrared light.
"We use the Earth's history as a key to finding life in the universe," said Lisa Kaltenegger, co-author of the research, astronomer at Cornell University, in a statement. . "By examining how life has changed Earth's biosignatures over time, it helps us determine which planets are most likely to show the most powerful signs of life, which ultimately gives us the best chance of locating with successful life, if it is there. " [Earth’s Plant Life from Space in Photos: NASA Satellite Images]
The two scientists behind the new research examined how the red edge of the Earth's vegetation, perceived by an alien, would change over time as the plant's life evolved and evolved. The first green plants, such as mosses, produced a very weak red edge signal from the vegetation. But now, 400 or 500 million years later, modern plants and trees produce a signal about twice as powerful. They also feed, house and dress human beings and many other forms of life.
"Our work shows that as plants evolved on Earth, the signal of vegetation revealing their presence became stronger, making older exoplanets really interesting places for vegetation research," Kaltenegger said.
And the researchers believe that the signal will become even more noticeable if the Earth continues to warm up and dry up, as cactuses particularly reflect this near-infrared light. For hopeful astrobiologists, this is not bad news because even today, it would be difficult to see the red edge of the Earth's vegetation.
However, even taking into account different types of plants and partial cloud cover, scientists discovered that the Earth had a different appearance from the Earth compared to other planets in the solar system – a promising sign for using this technical.
"Observing an exoplanet is harder, but telescope technology is better at detecting tiny signals," said co-author Jack O'Malley-James, an astronomer at Cornell University. "And taking into account the changing landscapes of the Earth in our models will facilitate the detection of future vegetation on other worlds."
The research is described in an article published Sept. 12 in the journal Astrobiology.
Email Meghan Bartels at [email protected] or follow her. @meghanbartels. follow us @Spacedotcom, Facebook and Google+. Original article on Space.com.
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