2 New theories come up about how earth got its moon
The mysteries about ‘how and when the moon was formed’ have been one of the most sought after secrets. Various theories came up but none of them was very convincing.
Various theories proposed about Earth and Moon:
- Fission theory
- Capture theory
- Co-accretion theory
- Giant impact hypothesis
Giant impact hypothesis, most convincing theory till now:
- Moon was created as a result of collision between a Mars-sized protoplanet called Theia and Earth.
- The collision sent debris from both bodies into space, which merged to form the moon.
- For this theory to be true, the composition of Earth and the moon should be different; but, studies show an almost identical match between the rocks from Earth and moon.
Two new theories were recently published back to back. One in journal Nature supported the giant impact theory whereas the other one in journal Nature Geoscience questions the giant impact theory, claiming that there were multiple small collision over a period of time.
Study published in Nature Geoscience:
- Moon was formed with material from the Earth itself.
- Over a period of millions of years, many small objects collided with Earth at high velocity.
- These collisions mined large amount of material from Earth leading to small moonlets
- These small moonlets, in turn, merged to become the moon.
Study published in Nature:
- This study tries to validate giant impact theory.
- According to this study, Earth and Theia were largely made of same kind of material.
- The claim is based on the study of abundance of oxygen isotopes, the yardstick for determining a rock’s origin.
Propositions about formation of the moon have been always hard to prove. To reach at final conclusion we will have to wait for more convincing evidences after more research on these theories.