As we go about our daily lives, we may not think about the Earth itself very often. But this planet is the foundation of our life. The air we breathe, the water we drink, and the gravitational force that binds us to the Earth. Until now, researchers believed it took more than 100 million years for Earth to form. Additionally, water was believed to be dispersed by lucky collisions with water-rich asteroids such as comets. But a new study from the University of Copenhagen suggests that this may not have happened entirely by chance.

“We show that the Earth was formed by the very rapid accumulation of tiny one-millimeter pebbles. According to this mechanism, the Earth was formed in just a few million years. Based on our findings, it appears that the presence of water on Earth is a byproduct of its formation,” says the Globe Institute. Martin Bizzarro, a professor and one of the researchers behind the new study.

The results of the study show not only that the Earth was created much faster than previously thought, but also that the presence of water was a predictable result of the formation process. This is important information because it tells us something about planets outside our solar system.

“Thanks to this new planet formation mechanism, the chances of habitable planets in the galaxy are much higher than we previously thought,” says Martin Bizzarro.

Habitability is the potential of a planet to have the necessary components for life to thrive on its surface. One of the most important substances for life is water.

“People have long debated how planets formed. One theory is that planets were formed by the gradual collision of bodies, and their size gradually increased over 100 million years. In this scenario, the presence of water on Earth would require some sort of random event,” he says.

An example of this would be comets, which are icy bodies, bombarding the Earth’s surface at the end of their formation.

“If Earth formed this way, it would be great to have water on Earth. It makes the chances of water existing on planets outside our solar system very low,” says Martin Schiller.

Instead, the researchers behind the new study offer a new theory of how the Earth was created.

“There was a disk around the young sun from which planets grew. The disk was filled with tiny dust particles. When a planet reaches a certain size, it acts like a vacuum cleaner, sucking up all the dust very quickly. This causes it to become Earth size in just a few million years,” says Ph.D. student Isaac Onyette, who is the corresponding author of the study.

This absorption of fine dust particles not only played an important role in the formation of the Earth, but also allowed water to reach our planet.

“The disk also contains many ice particles. The vacuuming effect pulls away some of the ice as it attracts dust. This process favors the presence of water during Earth’s formation, rather than relying on a random event 100 million years later to disperse water,” says Isaac Onyette.

With new knowledge and understanding of the mechanisms, the chances of water being found on other planets are much higher.

“This theory would have predicted that when you create an Earth-like planet, it will have water on it. If you go to another planetary system with a planet orbiting a sun-sized star, then if the planet is at the right distance, there must be water,” says Martin Bizzarro.

The researchers used silicon isotopes as a tool to understand the mechanisms and timescales of planet formation. By analyzing the isotopic composition of more than 60 different meteorite and planetary bodies, the researchers were able to establish genetic links between rocky planets such as Earth and Mars and other celestial bodies. This approach allowed the researchers to determine the type of building blocks that came together to form Earth and the process by which they came together. Source