Finding Twin Earths: Harder Than We Thought

Cambridge, MA - Does a twin Earth exist somewhere in our galaxy? Astronomers are getting closer and closer to finding an Earth-sized planet in an Earth-like orbit. NASA's Kepler spacecraft just launched to find such worlds. Once the search succeeds, the next questions driving research will be: Is that planet habitable? Does it have an Earth-like atmosphere? Answering those questions will not be easy.

In a new study, L. Kaltenegger (Harvard-Smithsonian Center for Astrophysics) and W. Traub (Jet Propulsion Laboratory) examined the ability of JWST to characterize the atmospheres of hypothetical Earth-like planets during a transit, when part of the light of the star gets filtered through the planet's atmosphere. They found that JWST would be able to detect certain gases called biomarkers, such as ozone and methane, only for the closest Earth-size worlds.


Source:
- http://www.cfa.harvard.edu/news/2009/pr200909.html
- http://www.eurekalert.org/bysubject/space.php