ANALYSIS: Kepler-62 is a Ripe SETI Target
"It's awesome that we have gone from nothing less than 20 years ago to being able to talk about planets in habitable zones and even have some planets that may be in habitable zones," astrophysicist Sara Seager, with the Massachusetts Institute of Technology, told Discovery News.
In related research, Seager points out that with such a diverse collection of exoplanets found so far, scientists' thinking about habitable zones may be too narrow.
"Because we've found so many different types of planets, we're going to miss out on habitability if we don't take a more broad view," Seager said.
Ultimately, scientists want to search the atmosphere of Earth-like planets for telltale chemical signatures of oxygen and other signs of life.
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"We don't know exactly what to look for but our instruments are general and we can look for gases that don't belong," Seager said.
Potentially life-bearing worlds, however, may not necessarily have the same pressures and atmospheric compositions as Earth, and could be as far from a sun-like, parent star as Jupiter, for example.