Earth 60 Million Years Older than Previously Thought
A group of scientists, based on the well-known collision between Earth and a Mars-sized celestial body some billions of years ago, have determined that Earth is in fact 60 million years older than previously thought.
Another recent study describes how scientists from Harvard University identified an echo of ancient Earth based off an isotopic signal. In this current study, geochemists from the University of Lorraine in Nancy, France have also based their findings on an isotopic signal, this time determining that previous age estimates for both the Earth and the Moon are way off.
It's difficult to ascertain information about early Earth and past events from "deep time," so scientists have had to rely on standard methods, such as measuring the changes in the proportions of different gases (isotopes) which survive from the early Earth.
Using this technique, lead researchers Guillaume Avice and Bernard Marty analyzed xenon gas found in South African and Australian quartz - dating back to 3.4 and 2.7 billion years, respectively - which served as a "time capsule" of sorts and allowed them to compare isotopic ratios of xenon with those which existed billions of years ago.
Past estimates had indicated that the formation of the Earth' s atmosphere took place around 100 million years after the solar system was created. As the atmosphere would not have survived the Moon-forming impact, this revision puts the age up to 40 million years after the solar system formation - meaning the Earth is actually 60 million years older than previously thought.
Though, Avice notes that "it is not possible to give an exact date for the formation of the Earth," according to a press release.
And though this discovery may seem inconsequential to the laymen's eyes, Marty assures us that it is a big deal.
"This might seem a small difference, but it is important," he explained. "These differences set time boundaries on how the planets evolved, especially through the major collisions in deep time which shaped the solar system."