Scientists Find New Clues In Old Mystery Of How Earth Got Its Water
About three-quarters of the Earth’s surface is covered with water. But how did it get there?
While some scientists believe water was delivered by icy space rocks smashing into the planet after it was formed, others have argued that water has been on Earth since its formation — and new research indicates they might be right.
An international team of scientists has found new evidence that water may have been a fundamental part of Earth since its beginning some 4.5 billion years ago.
“Our data suggest that the majority of Earth’s water was sourced from water molecules stuck to the surface of dust particles,” Dr. Lydia Hallis, the earth scientist at the University of Glasgow in Scotland who led the research, told The Huffington Post. “These dust particles eventually accreted together to form the Earth. So the planet’s water was brought in during Earth’s initial formation.”
For the study, which was published Friday in the journal Science, researchers examined volcanic rocks from Baffin Island off the Canadian coast and Icelandic lava. They noted that the rocks were from ancient sources beneath Earth’s surface and have remained untouched since the planet’s formation.
Using an advanced instrument called an ion microprobe, scientists took a close look inside the rocks to detect any chemical traces of early water, including its hydrogen composition.
In addition to finding such traces, they determined that the water’s chemical composition had very little of a hydrogen isotope called deuterium, which is sometimes called “heavy hydrogen.” Deuterium can be linked to different planetary bodies in space, but the amount found in the water suggests that it was not carried to Earth from elsewhere.