Copernicus Revisited: Is Earth Special?

Nearly 500 years ago, Nicolaus Copernicus published his disruptive theory that Earth is not the center of the universe. This ‘Copernican demotion’ has held fast over the centuries, as astronomers have learned that there is nothing particularly remarkable about Earth or even the Milky Way galaxy. In the last two decades, however, a new test of the Copernican principle has emerged: the discovery of an abundance of planets orbiting other stars. These discoveries allow us to put Earth in context and evaluate whether the formation, architecture and present-day characteristics of our solar system are, in fact, typical.

One of the biggest open questions is whether Earthlike exoplanets have water, a key ingredient for life. Thanks to the revolutionary new observing capabilities of the James Webb Space Telescope (JWST), it is possible to characterize the atmospheres of Earth-sized worlds for the first time. In this Presidential Lecture, Laura Kreidberg will share the latest observations of rocky exoplanet atmospheres from JWST, discuss the implications of their water abundances compared to the Earth’s, and answer the question, “Was Copernicus wrong?”