A synestia is a hypothesized rapidly spinning doughnut-shaped mass of vaporized rock. The term was coined in 2017 by Sarah T. Stewart-Mukhopadhyay, taken from Hestia, goddess of the hearth, combined with syn- meaning together.[1] In computer simulations of giant impacts of rotating objects, a synestia can form if the total angular momentum is greater than the co-rotational limit.[2] Beyond the co-rotational limit, the velocity at the equator of a body would exceed the orbital velocity.[3]
In the case of a synestia, the result is an inner region rotating at a single rate with a loosely connected torus orbiting beyond it.[4] Synestias also have differences in the mantles, both thermally and in their composition, from previous terrestrial evolution models due partially to a lower interior pressure.[5]
- ^ "Where did the Moon come from? A new theory | Sarah T. Stewart". YouTube.
- ^ Boyle, Rebecca (23 June 2017) [25 May 2017]. "Huge impact could have smashed early Earth into a doughnut shape". New Scientist. Retrieved 7 June 2017.
- ^ Gough, Evan (24 May 2017). "Scientists propose a new kind of planet: A smashed-up torus of hot, vaporized rock". Universe Today. Retrieved 7 June 2017.
- ^ Lock, Simon J.; Stewart, Sarah T. (2017). "The structure of terrestrial bodies: Impact heating, corotation limits and synestias". Journal of Geophysical Research: Planets. 122 (5): 950–982. arXiv:1705.07858. Bibcode:2017JGRE..122..950L. doi:10.1002/2016JE005239. S2CID 118959814.
- ^ Lock, Simon J. (2018). The Formation, Structure and Evolution of Terrestrial Planets. Graduate School of Arts & Sciences (Ph.D. thesis). Harvard University.