That discovery in 2016, with water found in an old Canadian mine, indeed hinted at ancient water, possibly 2 billion years old. However, determining the exact age of the water was elusive, as it didn’t reveal its formation date.
Recent research by Cecilia Ceccarelli and Fujun Du indicates that much of the water on Earth, including what we drink, likely formed around 4.5 billion years ago during the early stages of the Solar System’s formation. This conclusion positions it as older than our planet itself.
Their findings involved extensive analysis of the Solar System’s formation and intricate chemical processes. For comprehensive details on their study and how they arrived at this age estimate, you can explore the link: Research Details.