Astronomers may find another Earth-like, habitable planet using a new scientific technique. Maps of distant planets could be created to determine its surface's features.
New software can analyze and form a rough map of a planet outside of our solar system or "extroplanet," based on its reflected starlight. "Rotational is unmixing" is capable of calculating a planet's surface features by examining the reflections of changing colors. Different surface features such as land or oceans give off different colors.
The software was presented at a meeting by planetary scientist Nicolas Cowan at the American Astronomical Society in Long Beach, Calif. He developed it based on an existing technique used to differentiate natural surfaces from unnatural ones in Earth's satellite images. It's not a conventional map, but a rough idea what the planet's surface may look like.
"It's not like a map that you can use to land a spacecraft on a planet ... but it's better than nothing," Cowan said.
When applied to NASA's images of the Earth, "The analysis told us there were three important features and their spectra look an awful lot like land, ocean and clouds," said Cowan.
In a study published Thursday, March 14 in the journal Science, researchers tested the technique on a solar system 130 light-years away, HR 8799, where four planets exist. Water vapor and carbon were detected on one of the outer planets, HR 8799c.
"We have broken the light from the planet down to such a fine level of detail that the chemical fingerprints of the molecules in the atmosphere are breathtakingly sharp and distinct. This is important because it requires data of this quality to truly probe the makeup of a planetary atmosphere, and in turn, say something about how the planet formed," said Quinn Konopacky of the University of Toronto.
Astronomers have discovered 800 exoplanets so far. Using the new mapping technique may help scientists find another Earth-like habitable planet.