Synestia

A Synestia is a hypothetical bunch of vaporized rock in shape of a donut spinning around. According to studies, A synestia was an early process for the formation of the Earth and Moon in the giant-impact hypothesis. In that model, a synestia formed following a collision with an object of high speed and energy. The synestia's surface temperatures are contained by the boiling point of rock, around 2,300 Kelvin.

As the synestia cooled by radiating heat to space, lava droplets formed in its outer layers and then rained inward over a period of tens of years, causing the synestia to collapse.  Mass remaining outside the roche limit of the inner region accreted to form small objects, and then combined to form the Moon. The Earth re-formed later, once the synestia had cooled enough to fall within the co-rotational limit. By this theory, the Moon having formed within a cloud of gas and rock that originated from the Earth is why its materials are similar to those of the Earth. The later formation of the Earth (after the synestia cooled) is because it has accreted more elements with low boiling points than the Moon.

The term was made in 2017 by Sarah T. Stewart-Mukhopadhyay, taken from Hestia, goddess of the hearth, combined with syn- meaning together.

 Composition 
A synestia is composed of three areas: The inner area called the corotating region, a middle area called the transition region, and the area farthest out, known as the disk-like region. The corotating region rotates as a solid body. It is by hot vapor and high entropy levels, as well as higher relative speeds.

The "transition region" changes between the corotating region and ring-like region. in most simulations, the angular velocity and temperature follow a smooth gradient, both decreasing with radius. The temperature gradient is created by the mixture of hot vapor from the inner regions with colder condensed material from farther out. in this turns equally into a vapor. This turns into the disk-like region which its color can be different with different conditions for angular momentum, mass, and entropy.

References

Category:Outer space