Fact #38
July 14, 2026The Water You Drink Could Be Older Than the Sun
Some of the water molecules in your glass today may have formed before our Sun even existed. Scientists have found that a significant portion of Earth's water likely originated in the icy cloud of gas and dust that existed before the Solar System formed billions of years ago. Not all of this ancient water, though, was lost; some of it eventually became a part of asteroids, comets, and Earth.
Mini Facts
1
Water molecules are incredibly stable and can survive for billions of years.
2
Scientists traced this ancient origin by studying the ratio of hydrogen to its heavier isotope, deuterium.
3
Much of Earth's water was likely delivered by water-rich asteroids and other primitive Solar System bodies.
4
Researchers estimate that 30-50% of Earth's ocean water may predate the Sun.