NEW: February 28, 2018
Graduate student Simon Lock and coauthors present a new model for lunar origin within a terrestrial synestia. The model was developed by a multidisciplinary team of physicists, cosmochemists and dynamicists and emphasizes the crucial link between the pressures and temperatures of the environment around the growing Moon and the final composition of the Moon.
The Moon accretes within a synestia, a special type of astronomical body that is created by a giant impact. The Moon’s chemistry can be explained by formation at the high pressures and temperatures of the synestia.
Image by Sarah Stewart. Modified from NASA PIA 20700.
Graduate student Simon Lock and Sarah Stewart describe a new type of planetary object that is created by a giant impact: a synestia. This structure is not like a planet or a traditional planet with an orbiting disk, it something distinct that has different internal structure and dynamics than other planetary objects.
Where did the word synestia come from?
The name synestia means connected structure. The word is derived from Hestia, the Greek goddess of the hearth, home, architecture and syn means together.
The initial shape of an impact-generated synestia is a biconcave disc. A synestia will change shape as it cools over time.
Image by Simon Lock.
Sarah Stewart’s research group investigates the formation and evolution of planetary bodies. Our primary techniques are shock wave experiments to measure material properties and numerical simulations of planetary processes. We tackle a broad range of problems in planetary science by focusing on understanding the feedbacks between physical processes and changes in material properties.
We have a new model for the tidal evolution of the Moon, published in Nature. The model begins with a giant impact that tilts the Earth about 70 degrees from the ecliptic. Learn more about the Origin of the Moon. (Image from eskipaper.com)