In the search for Earthlike exoplanets, GJ 436b has much to tell us
Although we have yet to find an exoplanet, or planet outside our solar system, that is small and cool enough to resemble Earth and possibly host life, planetary scientists say it could happen within the next decade. They are preparing for that possibility by learning as much as they can about the atmospheres of progressively smaller exoplanets that can be thought of as stepping stones on the path to discovering — and making sense of — an Earth twin.Recently, a team of researchers, including Sara Seager, the Ellen Swallow Richards Associate Professor of Planetary Science in the Department of Earth, Atmospheric and Planetary Sciences, and postdoctoral researcher Nikku Madhusudhan, studied the atmosphere of GJ 436b, an exoplanet located about 30 light years away that is similar in size to Neptune, which is less than four times the diameter of Earth. Although they are large planets with hydrogen-rich atmospheres, Seager describes...