When did liquid water first exist on Earth’s surface?

While the exact timing of the appearance of liquid water on Earth’s surface remains a subject of scientific study, evidence suggests it existed very early in the planet's history.

Although direct geological records for this period are scarce, some scientists point to zircon crystals discovered in Australia that are dated to more than 4.4 billion years ago as evidence for the presence of stable continents and liquid water during the Hadean Eon.12

Other researchers note that while there is no direct physical evidence for water between 4.6 billion and 3.9–4.0 billion years ago, the existence of 3.85-billion-year-old marine sediments and pillow lavas in Greenland confirms that liquid water was present by that time. The formation of these early oceans is generally attributed to the cooling of Earth's surface, which allowed water vapor—released through volcanic outgassing or delivered by celestial impacts—to condense and accumulate in surface depressions.34526