Scientists proposed new type of planetary object

How planets can form from a series of giant impacts?


In a new study. scientists have confirmed the existence of a new, huge, spinning, donut-shaped mass of hot, vaporized rock, formed as a planet-sized object. Dubbed as Synestia, it is a rapidly spinning donut-shaped mass of vaporized rock.

Scientists explore how planets can form from a series of giant impacts. The various hypothesis of planet formation suggests that planets such as Earth, Mars and Venus formed early in the solar system when smaller objects collide into each other. These collisions were violent enough that they resulted in melted and partially vaporized, eventually cooling and solidifying to the nearly spherical planets we know today.

Scientists were interested in collisions between spinning objects. A rotating object has angular momentum, which must be conserved in a collision. Think about a skater spinning on ice: in the event that she broadens her arms, she moderates her rate of spin. To spin faster, she holds her arms near to her side, however, her angular momentum remains consistent.

Presently consider two skaters turning on ice: on the off chance that they seize one another, the precise force of every skater includes with the goal that their all-out rakish energy remains the equivalent.

In the new investigation, scientists demonstrated what happens when the “ice skaters” are Earth-sized rocky planets colliding with each other huge items with both high vitality and high angular momentum.

They observed the statistics of giant impacts and found that they can form a completely new structure. Over a range of high temperatures and high angular momenta, 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.

The key to synestia formation is that some of the structure’s material goes into orbit. In a spinning, solid sphere, every point from the core to the surface is rotating at the same rate. But in a giant impact, the material of the planet can become molten or gaseous and expands in volume. If it gets big enough and is moving fast enough, parts of the object pass the velocity needed to keep a satellite in orbit, and that’s when it forms a huge, disc-shaped synestia.

Sarah Stewart, a planetary scientist at the University of California Davis said, “Most planets likely experience collisions that could form a synestia at some point during their formation. For an object like Earth, the synestia would not last very long – perhaps a hundred years – before it lost enough heat to condense back into a solid object. But synestia formed from larger or hotter objects such as gas giant planets or stars could potentially last much longer.”

“The synestia structure also suggests new ways to think about lunar formation. The moon is remarkably like Earth in composition, and most current theories about how the moon formed involve a giant impact that threw material into orbit. But such an impact could have instead formed a synestia from which the Earth and Moon both condensed.”

The study is published in the Journal of Geophysical Research: Planets, a journal of the American Geophysical Union.

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