Astronomers analysed ancient lunar and terrestrial rocks to trace the origin of Theia, the Moon’s precursor planet.
Theia disappeared billions of years ago, leaving no direct chemical evidence for scientists to study.
Researchers suggest Theia likely formed closer to the Sun than previously believed.
The planet struck early Earth about 4.5 billion years ago, scattering debris that formed the Moon.
Material from Theia mixed with Earth’s, leaving a shared chemical signature in both bodies.
The giant impact theory, first proposed over 50 years ago, explains the Moon’s creation.
Astronomers now use modern techniques to reconstruct Theia’s properties and its Solar System origin.
Jake Foster of the Royal Observatory Greenwich says researchers almost exactly pinpointed Theia’s birthplace.
He adds that scientists can track a planet that vanished 4.5 billion years ago.
Reverse Engineering Ancient Collisions
Researchers examined Apollo samples and Earth rocks, analysing isotopes as chemical fingerprints.
Earth and Moon rocks share nearly identical metal isotope ratios, complicating separation of Theia’s material.
The team studied isotopes of iron, chromium, zirconium, and molybdenum to model early Solar System scenarios.
They simulated hundreds of combinations to determine which could produce observed isotopic patterns today.
Materials forming closer to the Sun display distinct isotopic patterns from those farther out.
Comparing these patterns revealed that Theia likely formed in the inner Solar System.
Some previous studies suggested Theia originated farther from the Sun than Earth, but data now contradicts that view.
Insights into Planetary Formation
Scientists hope this analysis will guide future research into planetary growth and collisions.
Understanding Theia’s origin illuminates how planets evolve in the early stages of a solar system.
Researchers plan to apply these techniques to study other vanished or altered planetary bodies.
The study demonstrates how isotopic signatures unlock secrets of long-lost celestial objects.
Astronomers aim to expand knowledge of early Earth-Moon dynamics through these findings.
This work may refine models of Solar System formation and planetary evolution.
Ultimately, tracing Theia’s path helps explain the Moon’s chemical and physical composition.
