Cosmic clues to formation of the Earth
Zircon crystals that act like time capsules may reveal details of how the Earth was formed according to a new study.
The research from Dr Phil Sutton, Senior Lecturer in Astrophysics at the University of Lincoln and colleagues has been looking at the tiny crystals embedded in the Earth’s crust as the way to unlock the secret of our planet’s 230-million-year geological odyssey through the Milky Way.
The study, in collaboration with Curtin University, Australia, compares two sources of information; maps of hydrogen gas which trace the Milky Way’s spiral arms, and compositional data captured within the zircon crystals - some over four billion years old - preserving the chemical fingerprints of Earth’s crust.
The scientists found striking correlations between the two records, showing that the movement of our Solar System through the galaxy could be linked to major changes in our planet’s geology.
Dr Sutton explained: “It’s hard to prove that events in our galaxy can leave a mark on Earth but our research gives us a way to start exploring that idea.
“By studying tiny zircon crystals - minerals that can survive for billions of years - we can see subtle chemical clues that may reflect the Solar System’s journey through the Milky Way. It’s a reminder that Earth didn’t form in isolation but has been shaped by the wider cosmic environment around us.”
Due to the Solar System’s vast orbit around the galactic centre of the Milky Way, it can be challenging to understand Earth’s movement in this. The planet passes frequently through the dense spiral arms of our galaxy densely populated with stars and interstellar matter exerting gravitational forces which travel through the Solar System.
Each time the Solar System passes through these dense galactic arms, the disturbance may trigger waves of comets to crash into Earth from the distant Oort Cloud. Such impacts could melt and reshape the planet’s crust, leaving behind traces that geologists can still read today.
Chris Kirkland, Professor of Geochronology at Curtin University, added: “Zircon crystals are like time capsules. They hold clues about how Earth’s crust melted, reformed and interacted with water over billions of years.”
Overall, these findings point to a bigger picture of Earth’s evolution that alongside plate tectonics and the sun’s influence, the Solar System’s galactic travels may have quietly shaped our world deep within time.
The paper is published in the journal Physical Review Research and is available to read online: https://journals.aps.org/prresearch/abstract/10.1103/98c3-d9j2.