The colors of an exoplanet might be an important clue as to the kinds of microbial life that exist on that alien world, says new research by a team from the Max Planck Institute for Astronomy in Germany.
The researchers led by Siddharth Hedge and Lisa Kaltenegger have compiled a catalog detailing the colors of microbes on Earth as a means of detecting life on exoplanets and what form that life might take.
They noted that when seen from space, the Earth's reflection in the near-infrared indicates our atmosphere contains oxygen and therefore could host life.
The German team concentrated their work on the reflective spectra of microbes rather than plants because the former have been in existence for a much longer time or 2.5 billion years. Plants have been present on Earth for only 500 million years.
The Germans studied 137 types of microbes in temperate and extreme environments from around the world, all of which have their own methods of reflecting light.
This data was assembled into a catalog listing the reflectance spectrum, or unique color each species reflects from a distance.
"No one had looked at the wide range of diverse life on Earth and asked how we could potentially spot such life on other planets, and include life from extreme environments on Earth that could be the 'norm' on other planets, said Kaltenegger, the co-author of the study.
The team found out different colored bacteria prefers different temperatures. If an entire planet were covered by microbes, whatever conditions they lived under would affect their color, said Kaltenegger, as quoted by Wired.com.
The team also realized that if life exited on exoplanets, it would probably be in the form of germs like those that dominated Earth for most of its history.
New space and ground-based telescopes are set to begin exploring alien worlds in the next few years. These will allow scientists for the first time ever to identify signs of alien life, also by using the colors reflected by an exoplanet.
To launch in 2017, the Transiting Exoplanet Survey Satellite aims to find hundreds of Earth-sized exoplanets all orbiting stars at a distance that would allow for liquid water. That "habitable zone" or "Goldilocks zone" makes it at least plausible that life could exist on their surfaces.
Next generation terrestrial telescopes will actually be able to see the kinds of colors that Kaltenegger and Hegde's catalog covers.
Among these will be the Giant Magellan Telescope that will start observing in 2021. There's also the Thirty Meter Telescope in Hawaii that will be finished in a few years.
An invaluable tool will be the long-awaited James Webb Space Telescope scheduled for launch in 2018. JWST can detect gases in the atmosphere, including the byproducts of processes unique to living things such as germs and bacteria.
http://www.wired.com/2015/03/want-find-aliens-look-colorful-planet/