A new study published in this week's Science journal debunked theories that the Earth was once a dry planet a comet brought water to it, instead it revealed that Earth already had water long ago, which we inherited from tiny grains of dust that produced the Solar System.
How the Earth got wet and where water on the living planet had originated has long been a subject of various debates. The new study, led by planetary scientist Lydia Hallis, suggests that the origin of water is the same cloud of gas and dust that spawned the Solar System itself.
According to Gizmodo, the researchers rely on isotopes in studying and analyzing the origins of water. Geochemists make use of the ratio of hydrogen to deuterium as molecular fingerprint of water. Previous researches follow that water formed after a celestial impact, meaning Earth's water came from outer space because previous findings showed isotope of celestial or extraterrestrial rocks, for example, comets.
The new study, however, looked into a more unspoiled record of Earth's original water by analyzing the volcanic rocks from Iceland and Baffin Island in the Canadian Arctic. The identified volcanic rocks contain material deep inside the Earth's mantle, which are isolated in the entire history of the Earth.
Upon observation, the researchers vaporized the samples of lava rocks and then analyzed the water trapped inside. They discovered that the hydrogen isotope ratio from the water was light and was way lighter that the hydrogen isotope ratio of Earth's modern ocean water. This means that the origin of water is not an extraterrestrial rock, because according to the researchers, the hydrogen isotope ratio of water from comets are heavier.
They further argue that water was already present in our planet since the very beginning and what brought it was the same gas and dust that formed the Solar System.
