Have you ever heard of synestia? This new theory states that the moon was formed from a spinning cloud of vaporized rock from early Earth.
A new study published by researchers from the University of California-Davis and Harvard University presented a novel theory on the much-debated topic on how the moon came into being
New Model Of Lunar Formation
Contrary to previously known theories suggesting that the moon was formed from a collision of early Earth with an astronomical body more than 4.5 billion years ago, the new model explained that the moon originated from inside the Earth when it was still a spinning cloud of vaporized rock.
The researchers said the moon was formed from a planetary object called synestia.
"Our model starts with a collision that forms a synestia. The Moon forms inside the vaporized Earth at temperatures of four to six thousand degrees Fahrenheit and pressures of tens of atmospheres," says Simon Lock, a graduate student at Harvard.
"Once the Earth-synestia formed, chunks of molten rock injected into orbit during the impact formed the seed for the Moon. Vaporized silicate rock condensed at the surface of the synestia and rained onto the proto-Moon, while the Earth-synestia itself gradually shrank," the research stated.
This new postulation challenges the favored lunar formation hypotheses called Big Splash, stating that the moon was formed from the debris of the collision between Earth and Theia that is about the same size of Mars. The moon's chemical composition that is very similar to that of the Earth suggests that it was made from the same source material.
The Big Splash theory showed that 9.2 million years after the Big Bang, a protoplanetary disk was formed, followed by accretion of planets wherein these planets collided and merged to form bigger planets. Theia collided with a young Earth at an oblique angle. The debris from the impact reformed into two moons orbiting the Earth. The two lunar bodies collided, and the smaller moon was destroyed.
What Is Synestia?
The idea about synestia was first proposed in 2017 by Lock and study lead author Sarah Stewart, professor of Earth and Planetary Sciences at UC Davis.
This donut-shaped planetary object forms when early planet-sized objects collide with one another. The impact from the collision produces high momentum and high energy and that are enough to create a rapidly spinning mass of molten and vaporized rock that exceeds the rotation limit of a planet. A synestia can last for a couple hundred years. During its lifetime, it shrinks rapidly as the hot rock vapor condenses into liquid. The product of this phenomenon is a molten rock that is the moon.
This new model explains the pattern of the Moon's composition that are hard to resolve with current ideas.
"The Moon inherited its composition from the Earth, but because it formed at high temperatures it lost the easily vaporized elements, explaining the Moon's distinct composition."
However, this model is purely theoretical and still needs refinement, according to the researchers.
The study is published in the Journal of Geophysical Research - Planets.