Earth's Oldest Crust Dates to 4.4 Billion Years Ago

Earth's oldest known piece of continental crust dates to the era of the moon's formation.

    

Zircon crystals from the Jack Hills of Australia, like the one above, reveal that continents arose just 160 million years after our solar system formed, much earlier than previously thought.

PHOTOGRAPH BY JOHN VALLEY, UNIVERSITY OF WISCONSIN-MADISON