The origin of water on our planet has largely remained a mystery, but new research suggests it has been present on our planet since the very beginning.
A team of researchers used advanced ion-microprobe instrumentation to look at rocks from Baffin Island in Canada. They compared the ratio of hydrogen to deuterium in the water within the ancient rocks to what is seen in other planetary bodies in our solar system, the University of Hawaii at Manoa reported.
"The Baffin Island rocks were collected back in 1985, and scientists have had a lot of time to analyze them in the intervening years. As a result of their efforts, we know that they contain a component from Earth's deep mantle," said cosmochemist Lydia Hallis.
As these rocks moved to Earth's surface, they never encountered sedimentary input from crustal rocks, leaving them essentially untouched. This means the rocks could hold some of the most primitive evidence of water known to science and provide a window into Earth's earliest history.
"We found that the water had very little deuterium, which strongly suggests that it was not carried to Earth after it had formed and cooled. Instead, water molecules were likely carried on the dust that existed in a disk around our Sun before the planets formed. Over time this water-rich dust was slowly drawn together to form our planet," Hallis said. "Even though a good deal of water would have been lost at the surface through evaporation in the heat of the formation process, enough survived to form the world's water."
The findings were published in a recent edition of the journal Science.