Scientists have discovered a microscopic zircon crystal in Western Australia’s Jack Hills, dated to an astonishing 4.4 billion years, making it the oldest known fragment of Earth’s crust ever found. This tiny blue speck carries significant implications for our understanding of when Earth’s surface solidified and when it might have supported water and life.
The zircon, formed just 160 million years after the Solar System’s birth, predates the Moon’s formation and provides evidence that Earth’s molten surface cooled earlier than previously thought. This ancient find is reshaping our understanding of early Earth’s history.
Zircons are durable minerals that can survive extreme geological conditions for billions of years, making them ideal time capsules for Earth’s history. The discovery confirms that a solid crust and liquid water likely existed by 4.3 billion years ago.
The finding challenges the dominant view of early Earth as a hellish, unstable planet dominated by volcanic activity. Instead, it suggests that the violent early phase may have been relatively short-lived, with the crust forming and stabilizing within 200 to 300 million years after the planet’s formation.
This new evidence points to the existence of liquid water at the surface, possibly even oceans, during this early period. The rapid stabilization of the crust also opens up an earlier window for life to emerge. If Earth could support liquid water as early as 4.3 billion years ago, microbial life might have developed much earlier than previously theorized.
This discovery influences how we assess the habitability of exoplanets, especially those in turbulent environments. By demonstrating that a life-supporting environment can arise relatively quickly in a planet’s history, it provides new insights into the possibility of life existing elsewhere in the universe.
Source: https://indiandefencereview.com/4-4-billion-year-chunk-earth-oldest-piece