Earth and moon 60 million years older than first thought

(Photo Credit: NASA/JPL-Caltech/University of Arizona)

A new study shows that the creation of the Earth and Moon happened around 60 million years earlier than previously thought.

Geochemists from the University of Lorraine in France argue that previous age estimates for the Earth and the Moon are actually underestimates.

There is little “classical geology” dating from the formation of the Earth, therefore it becomes difficult to date early Earth events. To combat these difficulties, geochemists must rely on other methods, such as measuring changes in the proportions of isotopes (different gases) which survived from the early Earth.

Xenon gas, found in South African and Australian quartz, which had been dated as 3.4 and 2.7 billion years old was compared to current isotopic ratios of xenon. This allowed geochemists to calculate that the date of the impact which formed the moon is around 60 million years older than had been thought.

Guillaume Avice, who worked on the study, explained the new data. According to Avice, “The composition of the gases we are looking at changes according to the conditions they are found in, which of course depend on the major events in Earth’s history. The gas sealed in these quartz samples has been handed down to us in a sort of ‘time capsule’. We are using standard methods to compute the age of the Earth, but having access to these ancient samples gives us new data, and allows us to refine the measurement”.

“The xenon gas signals allow us to calculate when the atmosphere was being formed, which was probably at the time the Earth collided with a planet-sized body, leading to the formation of the Moon. Our results mean that both the Earth and the Moon are older than we had thought” Avice added.