4.5 billion years: The moon is probably almost as old as the solar system
Researchers are still not sure how old the moon is. However, there is now growing evidence that it is almost as old as our solar system.
(Image: NASA)
The moon is probably even older than assumed and was carved out of the earth only 65 million years after the formation of the solar system. This is the conclusion reached by two scientists from the Max Planck Institute for Solar System Research (MPS), who have now presented their research at a specialist conference in the USA. They have determined an age of 4.5 billion years for the moon. As other analyses have recently come to a similar conclusion, the theory of a "young moon" could be on the brink of collapse. This is according to the US science magazine Science. This theory states that the moon was only formed 200 million years after the solar system. Conclusive proof to the contrary could soon come from China.
Collision with Theia happened very early
As Thorsten Kleine and Jonas Schneider from the MPS now explain, they have determined minerals from the moon based on the decay of the rubidium isotope87Rb to strontium (87Sr). Regardless of which models they assumed for the formation of the moon, the age determined in this way was always 4.5 billion years. Kleine himself once assumed that the moon was formed much later, he explained to Science. Now his work is one of a growing number of studies that suggest that the moon was, so to speak, carved out of the Earth directly after it was formed.
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Science explains that initial analyses of lunar samples from the Apollo missions have indicated that the moon is 200 million years younger than the solar system. This would make it "young", as most analyses later suggested that the solar system had already "come to rest" around 100 million years after its formation. The gas giants had therefore stopped hurling large objects into the inner solar system. The gigantic impact of the protoplanet Theia on Earth must therefore have taken place beforehand and not 100 million years after this calming down. According to the usual explanations, the moon was formed during this collision.
In recent years, studies have increasingly indicated that the moon is older than assumed, writes Science. However, there is still no conclusive answer to the age question. This could be provided by the examination of the material that the Chinese probe Chang'e 6 brought to Earth last year. If the minerals found there fit the theory of an "old moon", this could provide the answer, the magazine quotes planetologist Steven Desch's assessment. More recent analyses of the Apollo samples have already indicated that the age originally determined was not correct.
(mho)
