Astronomers traced the origins of Theia, a planet that vanished billions of years ago.
Theia likely formed closer to the Sun than scientists previously believed.
Researchers in France, Germany, and the United States studied ancient Earth and Moon rocks.
They aimed to identify the birthplace of the planet that helped create the Moon.
The giant impact theory proposes Theia collided with early Earth 4.5 billion years ago.
Debris from the collision coalesced into the Moon while mixing with Earth’s material.
Theia’s disappearance left no direct chemical evidence, making its origin difficult to determine.
Jake Foster of the Royal Observatory Greenwich called the study exciting and precise.
He emphasized that scientists can now estimate Theia’s source despite its complete destruction.
Reverse Engineering a Vanished Planet
The team analysed isotopes from lunar samples brought back by Apollo astronauts and Earth rocks.
Isotopes act as chemical fingerprints revealing a planet’s formation environment.
Earth and Moon rocks share almost identical metal isotope ratios, complicating identification of Theia’s material.
Researchers used isotopes of iron, chromium, zirconium, and molybdenum to model early planetary scenarios.
They simulated hundreds of combinations between Earth and Theia to match current isotopic patterns.
Planets forming closer to the Sun experience different temperatures, creating distinct isotope distributions.
Comparing these distributions allowed scientists to locate Theia’s probable inner Solar System origin.
The study suggests Theia formed even closer to the Sun than early Earth.
This challenges earlier ideas that Theia originated farther from the Sun than Earth.
Illuminating Planetary Formation
Researchers hope this work improves understanding of early Solar System evolution.
The study may guide future research on planetary growth, collisions, and chemical mixing.
Astronomers argue that isotopic analysis can reveal hidden histories of vanished planets.
Tracing Theia’s origin helps explain the Moon’s formation and Earth’s early development.
This approach could extend to other early planetary bodies in our Solar System.
Researchers believe these methods deepen knowledge of how planetary systems evolve over time.
The findings offer a framework to study chemical and physical interactions during planetary formation.
Future missions may provide additional samples to refine these models and conclusions.
