- Earth formed almost entirely from inner Solar System material, not outer regions
- Study compared isotopic ratios in meteorites from Mars and Vesta with Earth
- Material from beyond Jupiter's orbit makes up less than 2% of Earth's mass
A new study by planetary scientists has brought researchers closer to understanding where the material that formed Earth originally came from, challenging earlier theories about the planet's origins. Scientists have long believed that while Earth formed in the inner Solar System alongside Mercury, Venus and Mars, a large portion of its material may have come from the outer Solar System, beyond Jupiter's orbit. However, the latest research suggests that Earth was likely formed almost entirely from material found in the inner Solar System, reported BBC.
The study focused on the chemistry of meteorites, which are rocks from space that have fallen to Earth. These meteorites are considered important because they are leftover pieces from the early formation of the Solar System and provide clues about how planets were formed.
Researchers from the Swiss university ETH Zurich compared the chemical composition of meteorites from Mars and Vesta, one of the largest objects in the asteroid belt, with Earth's composition. Planetary scientists Paolo Sossi and Dan Bower studied isotopic ratios in the meteorites. Isotopes are atoms of the same element that contain different numbers of neutrons and help scientists identify where celestial bodies originated in the Solar System.
The researchers found that Earth's material appears to come entirely from the inner region of the Solar System. According to the study, material from the outer Solar System accounts for less than 2% of Earth's mass, or possibly none at all.
Sossi said that their calculations made it clear that the building material of Earth originated from a single material reservoir.
Bower said the researchers were astonished to find that Earth is composed entirely of material from the inner Solar System and not from any combination of existing meteorites.
Sossi further said that their studies were actually data science experiments and that the team carried out statistical calculations that are rarely used in geochemistry despite being powerful tools.
According to the study, Earth is made entirely of non-carbonaceous material and there is no evidence that it formed from a combination of inner and outer Solar System material.
The findings suggest that Earth developed within a relatively stable system inside the dusty disc of debris surrounding the young Sun. The study also raises the possibility that volatile elements such as water may already have existed in the inner Solar System.
Scientists have long believed that Jupiter played a major role in shaping the Solar System because of its strong gravity. It is thought that Jupiter influenced the size of Mars, helped form the asteroid belt and divided the young Solar System into two separate material reservoirs.
The study explained that Jupiter created a gap in the dusty disc around the young Sun, preventing material from the outer Solar System from mixing with material in the inner Solar System.
According to the researchers, the new findings show that very little material from beyond Jupiter reached Earth.
Bower said that the calculations were very robust and relied solely on the data itself rather than physical assumptions, which are still not fully understood.
The study also found that Earth's composition closely resembles that of Mars and Vesta, while Venus and Mercury appear to follow the same pattern.
Paolo Sossi said that based on the analysis, researchers can theoretically predict the composition of Venus and Mercury. He added that the findings shed new light on the formation history of Earth and other rocky planets. Earth's Composition Closely Matches Mars, Suggests New Study On Planet's Origins
