4-billion-year-old Australian zircon crystals reveal fresh water on Earth 400 million years earlier than expected, suggesting early water cycle and dry land presence.

4-billion-year-old zircon crystals from Western Australia's Jack Hills show evidence of fresh water on Earth hundreds of millions of years earlier than previously believed, suggesting a water cycle and dry land existed at that time. This discovery, published in Nature Geoscience, challenges the theory that Earth was entirely covered by ocean four billion years ago and implies that landmasses and fresh water played a significant role in the emergence of life on Earth.