The source of most of Earth’s water is largely unknown, and a popular hypothesis suggests it was brought to the planet by ice-rich meteorites. But a new study refutes this idea. In fact, achondrites, a common type of stony meteorite, are among the driest extraterrestrial minerals, with a water content of no more than two micrograms per gram.

Scientists have studied achondrites

The research team examined samples of seven achondrites from at least five different planetary bodies, which were celestial bodies orbiting the solar system throughout its early history. Meteorites were molten during the fall to Earth due to strong radiation, and the absence of characteristic rounded inclusions, chondrules is explained by the complete or partial melting of the meteorite material.

To accurately measure the magnesium, iron, calcium, silicon and water content in the samples, the scientists had to carefully remove moisture from the surface layers of the meteorites using an oven and a powerful pump.

The paper’s authors say their findings have implications for understanding the spontaneous emergence of life, known as abiogenesis, and for searching for traces of life on other planets. The study also refutes the widespread hypothesis that meteorites are the main source of water filling Earth’s oceans.

It is customary to believe that if an object comes from distant regions of the Solar System, then it necessarily contains a lot of water. Our article confidently refutes this. When the substance of the meteorite melts, there is no moisture in it,
– says one of the authors, Sune Nielsen.

The study shows that while meteorites may have brought some water to Earth, the planet’s vast water supply was not its primary source. The article highlights the importance of continuing to study the origin of water on our planet and its importance for the development of life beyond borders.