The Earth and other extraterrestrial objects that formed during the early years of the solar system share the same chemical origins, according to a new study.
Audrey Bouvier, a cosmochemist at the Western University in Ontario, Canada, discovered that the Earth shares the same chemical origin with other primitive materials in the solar system–a finding that shatters previous scientific beliefs about the Earth’s origins.
“How the Earth was formed and what type of planetary materials were part of that formation are issues that have puzzled generations of scientists,” Bouvier, who is also curator of the Western Meteorite Collection and principal investigator at Western University’s Center for Planetary Science and Exploration, said in a news release.
“And these new isotopic measurements of meteorites provide exciting answers to these questions about our origins and what made the Earth so special.”
Neodymium-142 (142Nd) is one of the seven isotopes found in the chemical element neodymium, which is widely distributed in the Earth’s crust. The element is commonly used for magnets in commercial products such as microphones and in-ear headphones.
Through thermal ionization mass spectrometry, Bouvier and her colleague Maud Boyet found that the Earth and other planetary objects share the same initial levels of 142Nd.
In 2005, a small variation 142Nd was detected in chondrites–the stony meteorites that are considered essential building blocks of the Earth and terrestrial rocks. The findings were initially interpreted as an early differentiation of the chondrites and the interior of the Earth, which includes the crust and the mantle, within the first 30 million years of its history.
The results of the study, which was published in the journal Nature, showed that theses differences in 142Nd had already been present during the growth of Earth, and were not introduced later as what previous scientists believe.
Using improved measuring techniques, the researchers deduced that the different meteorological objects in the solar system incorporated the elements neodymium (Nd) and samarium (Sm) but with different isotopic compositions. These isotopic variations also demonstrate that the solar system had not been “uniform” during its earliest years and that materials formed from the oldest stars were incorporated in different proportions into the planetary building blocks.