A brand-new research sheds light on Earth’s water formation 

The long-standing mystery of where water came from on Earth may have finally been resolved. How? Well, brand-new research published in the Journal of Geophysical Research: Planets (published by the American Geophysical Union) reveals that the hydrogen in the water on the planet partially came from clouds of dust and gas that stayed behind after the Sun was created, a phenomenon regarded as the solar nebula.  

Okay, but why are scientists looking for the sources of hydrogen rather than oxygen? It is because they already know that oxygen is abundantly available in the solar system.  

Earlier, researchers revealed a theory that suggested that all of Earth’s water was sourced from asteroids as there are striking similarities between ocean water and the water found on asteroids. In fact, the ratio of deuterium (a heavier hydrogen isotope) to normal hydrogen often serves as an unusual chemical signature of water sources. And it turns out, this ratio in case of oceans on Earth is very close to the composition of water in asteroids.  

However, according to this latest study, scientists believe that the Earth’s oceans do not reveal the entire narrative of the hydrogen source. In fact, sources reveal that the hydrogen in the oceans does not represent hydrogen in the entire planet. For instance, the hydrogen deep inside the Earth, such as between core and mantle has negligible amount of deuterium, meaning that this hydrogen did not come from asteroids. Not only that, noble gases including helium and neon were found instead in large quantities. In the new study conducted by the School of Earth and Space Exploration and the School of Molecular Sciences of Arizona State University, scientists have tried to analyse these differences.  

As per the new model, many billion years ago, asteroids collided with one another and eventually broke apart to form planets. Now, this also resulted in chemical interactions between the hydrogen-rich atmospheres of the asteroids and the magma of the oceans that they created. Eventually, this magma attracted noble gases as well as the hydrogen from solar nebula and led to the birth of early atmosphere. This nebular oxygen eventually dissolved into the molten iron of the magma oceans and was finally pulled towards the centre of the Earth, from where it spread elsewhere.  

So, in conclusion, we can say that the hydrogen in Earth’s water came from two possible sources: asteroids and solar nebula. The study also suggests that exoplanets that do not have access to asteroid water may have gained it from their own solar nebula.