Where did Earth’s water come from?
There is so much water on our planet. It’s like, “Water, water, everywhere.” Where did all of that water come from?
— Ron Warten
Given that 71 percent of the Earth is covered by water and that water is the most abundant material on its surface, the planet perhaps should have been named “Water” rather than “Earth.”
The source of all that water is still somewhat of an unsolved matter, but there is widespread belief that the majority of it has come from the Earth itself, as water vapor from the exhalations of volcanoes over the last several billion years.
Lowell Observatory astronomer David Schleicher says, “The estimates I’ve heard are that perhaps 10 to 30 percent of the water on Earth comes from comets, which contain a good deal of ice. I’d say that’s fairly important.”
There is widespread belief that the majority of Earth’s water came from the Earth itself, as water vapor from the exhalations of volcanoes over the last several billion years.