August 24, 2022
Introduction:
Read more here: https://www.eurekalert.org/news-releases/962656(EruekAlert) New Curtin research has found evidence that Earth’s early continents resulted from being hit by comets as our Solar System passed into and out of the spiral arms of the Milky Way Galaxy, turning traditional thinking about our planet’s formation on its head.
The new research, published in Geology, challenges the existing theory that Earth’s crust was solely formed by processes inside our planet, casting a new light on the formative history of Earth and our place in the cosmos.
Lead researcher Professor Chris Kirkland, from the Timescales of Mineral Systems Group within Curtin’s School of Earth and Planetary Sciences, said studying minerals in the Earth’s crust revealed a rhythm of crust production every 200 million years or so that matched our Solar System’s transit through areas of the galaxy with a higher density of stars.
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“From looking at the age and isotopic signature of minerals from both the Pilbara Craton in Western Australia and North Atlantic Craton in Greenland, we see a similar rhythm of crust production, which coincides with periods during which the Solar System journeyed through areas of the galaxy most heavily populated by stars.”
“When passing through regions of higher star density, comets would have been dislodged from the most distant reaches of the Solar System, some of which impacted Earth.