Blaauw Lecture 2025

Every year, the Kapteyn Astronomical Institute organizes the Blaauw Lecture.
This is a lecture by an internationally renowned astronomer which everyone, including the general public, can attend. The level of the lecture is such that everyone should be able to understand it.

Professor Laura Kreidberg of the Max Planck Institute for Astronomy in Heidelberg, Germany, will give the Blaauw lecture 2025. The title of her lecture is: “Copernicus revisited: is the Earth special?”

Copernicus Revisited: is the Earth special?

Nearly 500 years ago, Nicolas 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. 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.

Thanks to the revolutionary capabilities of the James Webb Space Telescope (JWST), we are finally able to study other Earth-size planets in detail, and in particular search for and characterize their atmospheres. In this talk, I will give a status report on JWST observations of rocky planets. I will cover the latest results for the iconic TRAPPIST-1 system, the study of the surface of the airless planet LHS 3844b, the search for atmospheres on lava worlds, and observations of planets in the radius valley at the boundary of rocky and gaseous worlds. Taken together, these results provide a first picture of the building blocks available for the origin of life on terrestrial planets beyond the Solar System, providing essential context for how special Earth really is.