Prior to the detection of the first exoplanet two decades ago, our ideas about how planets form were largely based on the example of a single planetary system: our own. The subsequent discovery of hundreds more planetary systems has challenged these theories, revealing the incredible diversity of planets that nature produces. At the same time, new spacecraft missions in our solar system have allowed us to begin to probe the earliest days of its formation with a precision currently impossible for systems farther away. I am interested in combining these exquisite observations of our solar system with the rapidly-expanding exoplanetary census to better understand how planets form, why some systems look so different from our own, and how common the formation of Earth-like planets may be.
With Hilke Schlichting, I am working to understand a class of planets known as super-Earths. These worlds, which are larger than the Earth, are incredibly abundant in our galaxy, yet they have no solar system analog. Some super-Earths appear to be mostly rocky, but others have significant atmospheres of hydrogen and helium. We are investigating whether collisions between planets can boil off their atmospheres, potentially explaining this diversity.
In collaboration with Benjamin Weiss, I am also exploring the formation of our own solar system with data from the European Space Agency’s Rosetta mission to the surface of comet 67P/Churyumov-Gerasimenko. Comets like 67P are thought to be planetesimals—the early building blocks of planets leftover from the formation of our solar system 4.5 billion years ago. Specifically, we’re working to understand what magnetic measurements of comet 67P’s surface may reveal about the magnetic environment in the early solar system and the mechanism of planetesimal accretion.