While 71% of the Earth’s surface is covered by water, the main question still remains: Where did this water come from in the first place?
Scientists have come up with a number of theories over the years, ranging from the arrival of water on meteorites to the Earth producing its own early water. Daily Mail.
Now, scientists from the California Institute of Technology have taken a major step toward solving the mystery.
The researchers claim that Earth was formed from dry, rocky building blocks, suggesting that its waters must have arrived much later in the planet’s formation history.
“Major addition of volatiles essential to life, including water, only occurred during the last 15 percent (or less) of Earth’s formation,” the team said.
The formation of the Earth dates back to about 4.5 billion years ago, and scientists are still trying to understand the processes by which the planet was formed.
In the new study, the team found a lack of volatiles—chemicals that can easily evaporate, including water—in the depths of the planet.
However, they found that the upper mantle is abundant in volatiles.
This indicates that the Earth was formed from hot, dry rocky material, and that water came to our planet later, according to the team.
The researchers hope the findings will help unlock the mystery of how Earth – as well as other rocky planets in our solar system – formed. While we cannot easily enter the depths of our planet, magma deep in the Earth makes its way to the surface in the form of lava.