Friday, January 21

Earth’s water would come from the Sun

Earth’s water would come from the Sun

A new international study suggests that the solar wind, made up of charged particles from the Sun largely made up of hydrogen ions, created water on the surface of asteroid-borne dust grains, which slammed into Earth during the early days of the Earth. Solar system. This would be a probable and surprising source to unravel the mystery regarding the origin of water on Earth.

If we think of water as an element, obviously a fireball like the Sol it would not be the first thing we would relate to in our mind. However, scientific mysteries can often be solved in the least logical and predictable way: this could be the case of the origin of water on Earth, which has not yet been fully explained. Would our fiery king star be responsible for the existence of this vital element on the earth’s surface?

Related topic: Earth’s water was always hidden in its rocks.Related topic: Earth’s water was always hidden in its rocks.

Water in asteroids

According to a Press release from Curtin University in Australia, one of the academic centers that participated in this new study, recently published in the journal Nature Astronomy, scientists wondered why the Earth is so rich in water compared to others rocky planets of the solar system, including oceans that cover more than 70 percent of its surface. What is the source of so much water, largely responsible for the vital explosion that characterizes our planet?

One of the prevailing theories on this subject indicates that water was transported to Earth in the final stages of its formation in type C asteroids, which have a high carbon content and are approximately 75% of the known asteroids. However, analyzes performed on these bodies show that their isotopic fingerprint does not largely match the water found on Earth. It is worth remembering that this fingerprint shows the abundance of the different stable isotopes in a given atom or element.

Thus, there should be other sources to explain the abundance of water on Earth. According to the authors of the new study, the solar wind would have created water on the surface of tiny grains of dust included in asteroids with specific characteristics, which collided with the Earth during the process of formation of the planets. Consequently, this “solar” source would explain the presence of a large part of the water that exists on the earth’s surface.

On Earth and on other planets

To reach this conclusion, the scientists conducted an atom-by-atom analysis of tiny fragments of a near-Earth asteroid known as Itokawa. It is an S-type asteroid: they are bodies of rocky composition, which make up approximately 17% of the identified asteroids. The samples studied were collected by the Japanese space probe Hayabusa in 2010.

The researchers noted that an amount of water was discovered in the first 50 nanometers of the surface of the dust grains identified in the asteroid Itokawa that, when enlarged, would amount to about 20 liters for every cubic meter of rock. If this body has this amount of water, the hypothesis that this variety of asteroids could have transported water to Earth originated in the solar wind is not at all far-fetched.

Finally, the scientists highlighted that in addition to contributing to the resolution of the mystery surrounding the origin of the Water on Earth, the new theory could also help develop future space missions. Because the same space weathering process that created water on the asteroid Itokawa would have occurred on other airless planets, astronauts could process fresh supplies of water directly from dust on the surface of a planet or satellite, such as the Moon.


Solar wind contributions to Earth’s oceans. Daly, L., Lee, M.R., Hallis, L.J. et al. Nature Astronomy (2021). DOI:

Photo: the sun, solar winds and the asteroid Itokawa. Credit: Curtin University.

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