We know that our home planet has been the blue planet for at least 3.8 billion years, which was proved by the ancient sedimentary rock deposits and lava that cooled into characteristic pillow shapes, due to their interaction with water. But still Geologists keep debating to find out from where all of Earth’s water come from.
There are mainly two competing theories, the first one suggests that the water on Earth may have come from asteroids and comets that collided to the planet, but recent research has given more strength to the second theory which states that water was always present on Earth in its mantle rocks and was then gradually released to the surface as a consequence of the volcano eruptions.
Determining what was the source of the water, would not only help us understand it better, but it would also be a big help in the discovery of other planets that can support life as we know it.
Back in 1974, scientists found out that the Earth’s mantle contains more precious materials the previously expected, and that these elements are naturally attracted to iron, and so a big part of the material was pulled in the direction of Earth’s core.
Now, a new study from earlier this year, has shown us that the type of ruthenium (one of the materials attracted to iron) present in the Earth’s mantle has a different atomic signature than the similar material found on common asteroids from the outer solar system, which suggests that the materials on Earth came from the inner solar system, where volatile substances are rare, proving then that it is highly unlikely that they were the source of the water on Earth.
There is multiple evidence that the oldest materials on Earth, like zircon, have crystalized from the interaction of magma sources and water, and since those materials where between 4.1 and 4.3 billion years old, it’s more than likely that the water was already here by then.