Diana Valencia, a graduate student at Harvard, has been working with professor of geophysics Richard O’Connell in a study of the possible internal structure of large terrestrial planets around other stars. Their presentation “Internal Structure and Scaling Laws of Massive Terrestrial Planets” was given at the American Geophysical Union’s fall meeting. From the abstract: “The focus of this study is to calculate the internal structure of massive terrestrial planets starting from the knowledge acquired on the Earth and other solar system planets. With the use of equations of state for the Earth and physical laws we obtain radial structure profiles of mass, pressure and density, including all major phase changes for massive Earth-like planets.”
Why is this work important? Because the first mission likely to detect a terrestrial-type planet is Kepler, scheduled for launch in 2006. The spacecraft will attempt to detect such planets by watching for their transit across a distant stellar disk. And it’s clear that the first planets we’ll find using its methods will be massive objects with tight orbits around their parent star. Creating a model for the development and structure of such worlds will be a significant step in understanding what we’re seeing when the first Kepler results come in.