Water-soaked dust in Earth’s mantle hinted to the formation of oceans.
(Mirror Daily, United States) – It’s one of the most common yet mysterious source of our planet, and now researchers place our water’s origins in ancient dust, as opposed to being brought here by comets or meteors. The prevailing theory has been that space objects have crashed onto Earth, and essentially brought water molecules along with them.
It has lead to many questions as to why then our planet is the only one dominated by water, covering over two thirds of Earth’s surface.
However, a team of researchers mean to challenge that suggestion, bringing their own theory to the table. Instead, their study suggests that water was already here, hidden deep within the Earth’s mantle.
They analyzed lava samples taken from deep within the planet. The rocks were collected back in 1985 from Baffin Island, in Canada’s Arctic that scientists have studied for a long time. According to lead author of the study, Lydia Hallis, from the University of Glasgow, the samples are some of the “most primitive rocks” ever found on Earth. This allowed them for an extensive research on how water might’ve once been.
Using advanced ion-microprobe instrumentation, the researchers were able to look into the tiniest details of water-soaked dust grains inside the rocky samples. They studied the very minute amounts of water inside, determining the deuterium to hydrogen ration (D/H). Deuterium is an isotope of hydrogen, otherwise known as ‘heavy hydrogen’. The D/H ratio in core samples of planets could tell a lot about their history.
It’s believed that deuterium was created and released in the wake of The Big Bang, and that it was not spread evenly throughout galaxies. It slithered throughout the dust and gas that led to the formation of planets. Where Earth is concerned, many suggest that the D/H ratio has changed through time, mainly because of the movement of tectonic plates.
However, due to the depth of the lava samples, researchers believe that they have remained virtually unaltered by time or other events. They presented with lower amounts of deuterium than previously found, which may just be the original signature for Earth’s D/H ratio. This is in spite of the fact that today’s water essentially matches the water molecules and D/H ratio found in outer space.
According to Hallis, the fact that the water had so little deuterium suggests that it was not “carried to Earth after it had formed and cooled”. Instead, it was already there, on the dust that surrounded the Sun before the planets formed. As time progressed, they essentially banded together and formed what our planet is today.
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