Rare isotope signature reveals secrets of Earth's early days
MIT researchers, led by Nicole Nie, found a rare potassium isotope signature in ancient rocks from Greenland, Canada, and Hawaii.
These rocks are slightly lacking in potassium-40—a subtle but important difference that hints at hidden secrets from Earth's earliest days.
Tiny detail hints at big history
Using thermal ionization mass spectrometry and dissolved powdered samples, the team noticed the deficiency was "like spotting a single grain of brown sand in a bucket rather than a scoop full of yellow sand."
This tiny detail suggests some of Earth's original building blocks survived billions of years of planetary upheaval.
Impact on planet's formation
This discovery challenges the classic story that a massive impact 4.5 billion years ago completely melted and mixed Earth's materials.
Instead, it looks like pockets of ancient, untouched material are still buried deep below us—offering a fresh look at how our planet (and maybe others) really formed.