In rare cases, the Earth was hit by a large meteorite or asteroid. However, space dust impacts our planet daily, bringing micrometeorites that fall on the surface of our planet.
A team of researchers has explored some of the oldest samples of micrometeorites in an attempt to learn how they interacted with the gases present in the atmosphere of our planet as they zipped across the sky.
Previous data signaled the presence of oxygen, contradicting theories that argued that there were no traces of this gas in the early days of formation.
The researchers discovered that the atmosphere through which the meteorites traveled was rich in carbon dioxide, a trait that is consistent with the chemical structure of the atmosphere in the distant past. With an age of more than 2.7 billion, the micrometeorites are quite old.
Scientists collected the micrometeorites from the limestone sites found in the Pilbara area, Western Australia.
Carbon dioxide was prevalent in the ancient Earth’s atmosphere
The researchers reached our planet during the Archean period when the Sun was considerably weaker in comparison to modern times.
The team who made the initial discovery argued that the meteorites prove that oxygen was present in the atmosphere when they arrived.
This claim contradicted the current perspective related to the history of our planet since the Great Oxidation Event took place almost 500 million years later. By learning more about the conditions encountered on Earth in the past, researchers hope to learn more about the factors that favored the appearance of life.
It is known that the first forms of life formed almost 3.8 billion years ago, but the mechanics behind the genesis remain a mystery for now.
While the previous study argued that the presence of oxidation on the surface of micrometeorites proves that molecular oxygen could be found within the atmosphere, the new paper argues that the same phenomenon may have been caused by carbon dioxide. More data can be found in the article, which was published in a scientific journal.