Although Gliese 581g is the most Earthlike planet to be
discovered to date, it's unclear whether the planet is
habitable. Just because the planet is relatively similar in mass
to Earth doesn't mean it can host life. Although Earth and Venus
are about the same mass and size, the surface of Venus is too
unbearably hot for life to survive there. In fact, the hardest
part about the quest to find life elsewhere in the universe may
be confirming whether an Earth-sized planet is habitable. The
only way to find that out is by studying the planets atmosphere,
an area of research that Sara Seager, the Ellen Swallow Richards
Professor of Planetary Science in MITs Department of Earth,
Atmospheric and Planetary Sciences and professor of physics, has
pioneered over the past 15 years. Although Seager has mostly
studied the atmospheres of massive exoplanets known as hot
Jupiters, which are too hot and gaseous to host life, she
considers these observations as valuable practice for studying
smaller exoplanets. We are just test