A team of Swiss planetologists has advanced in studying the origin of the World Ocean. They analyzed the composition of meteorites found on Earth, focusing on the ratio of manganese to chromium in them. These elements are considered volatile substances, and their presence varies depending on the distance of a celestial body from the Sun.

The research revealed that the manganese-to-chromium ratio in meteorite rock is on average 0.8. In contrast, the same ratio in Earth’s rocks is about half of that, indicating that the original material was drier with a higher concentration of chromium.

This finding led the scientists to conclude that Earth was originally much less wet than it is now and that water on the planet arrived as a result of external impacts.

Modeling of planetary formation in the Solar System suggested that if water had been accumulating gradually as the planet grew, its amount would have been much less than it is today. The study was published in the journal Science Advances.

It was also concluded that comets could not have been the cause of the World Ocean's formation, as most of these bodies come from Neptune’s orbit and contain a lot of deuterium, which is extremely rare in Earth's water.

Instead, scientists proposed the hypothesis that the World Ocean formed as a result of a collision with another celestial body around 4.5 billion years ago. However, this scenario would only be possible if the colliding object contained a lot of manganese and had a mass about 10 times smaller than Earth’s mass.