University of California, Davis | 2017 May 22
There’s something new to look for in the heavens, and it’s called a “synestia,” according to planetary scientists Simon Lock at Harvard University and Sarah Stewart at the University of California, Davis. A synestia, they propose, would be a huge, spinning, donut-shaped mass of hot, vaporized rock, formed as planet-sized objects smash into each other. ...
Lock and Stewart study how planets can form from a series of giant impacts. Current theories of planet formation hold that rocky planets such as the Earth, Mars and Venus formed early in the existence of our solar system as smaller objects collided with each other. These collisions were so violent that the resulting bodies melted and partially vaporized, eventually cooling and solidifying to the (nearly) spherical planets we know today.
Lock and Stewart are particularly interested in collisions between spinning objects. A rotating object has angular momentum, which must be conserved in a collision. ...
The researchers found that over a range of high temperatures and high angular momentum, planet-sized bodies could form a new, much larger structure, an indented disk rather like a red blood cell or a donut with the center filled in. The object is mostly vaporized rock, with no solid or liquid surface.
They have dubbed the new object a “synestia,” from “syn-,” “together” and “Hestia,” Greek goddess of architecture and structures. ...
Researchers Propose New Type of Planetary Object
American Geophysical Union | 2017 May 22
The Structure of Terrestrial Bodies: Impact Heating, Corotation Limits and Synestias - Simon J. Lock, Sarah T. Stewart
- Journal of Geophysical Research: Planets (online 22 May 2017) DOI: 10.1002/2016JE005239