The Earth is unique among known planets in having liquid water on its surface, a crucial reason for the existence of life. Explaining how this came to be, and predicting conditions friendly to life elsewhere requires understanding the protoplanetary disk from which Earth and the other planets formed, a complex, interacting system of rocks, dust, gas, plasma, and magnetic fields in orbit around the young Sun. Many models by different scientific communities have addressed separate aspects of this problem, but none has integrated all the different physical, chemical, and mineralogical processes into a single, general, continuously improvable, three-dimensional, computational model.
Our imminent entry into the petascale computing era makes such a model practical for the first time. This project will be the first serious attempt to develop a complete, multi-physics model based on a global simulation of a protoplanetary disk. We will include three major physical processes. First is the turbulence driven by magnetic fields coupled to the partially ionized gas, which determines how fast the disk accretes onto the star and how well dust can stick together to form the building blocks of planets. Second is the radiative cooling of the disk, which determines the temperature of the disk, and is determined by how dusty the disk is. That, in turn, is controlled partly by the temperature. Third, the gas chemistry and the temperature, as well as the dust properties, determine the ionization of the gas, which in turn determines how turbulent the disk is. All of these processes will be included in a common computational framework. This framework will rely on a novel numerical algorithm for computing magnetized gas flows using simulated particles moving with the gas. This algorithm combines advantages and evades limitations of both traditional grid-based simulation codes and of more widely used particle methods such as smoothed particle hydrodynamics. Our team includes the inventor of this method.
With a new, integrated model, we will be able to better understand Earth's position and properties, the properties of other Solar System objects, and observations of extrasolar planetary systems.
The funding for this project will support the interdisciplinary training of a graduate student in the areas of meteoritics and astrophysics treated here. A collaboration between the host institution and two European institutions will be supported, with graduate students traveling in both directions for collaboration and training. Three undergraduate students will also participate in this research.
The research undertaken here will inform the exhibitions and education work of the PI and co-PI Ebel. Currently, their projects include a new Hayden Planetarium Space Show (estimated international viewership 7 million over 5 years, including 0.5 million NYC school children), a photo exhibit on the Cassini-Huygens mission to Saturn, as well as extensive work with the professional development and community education departments of the Museum, and mentoring summer REU students and interns.
