SPOKANE, Wash. (AP) -- Thousands of planets will likely be discovered in the next few years, and a new system is needed to better classify the ability of those worlds to support life, according to a Washington State University professor.
In a paper to be published in the December issue of Astrobiology, professor Dirk Schulze-Makuch and colleagues propose a new system that classifies some planets as either similar to Earth, or not similar but capable of harboring life.
"The first question is whether Earth-like conditions can be found on other worlds, since we know empirically that those conditions could harbor life," said Schulze-Makuch. "The second question is whether conditions exist on exoplanets that suggest the possibility of other forms of life."
About 700 exoplanets, those outside our solar system, have been discovered so far.