Water could be a natural byproduct of the formation of rocky planets, so it could be almost anywhere

Water could be a byproduct of the formation of all rocky planets, a new study proposes.

From everything we know about life today, water appears to be a key ingredient. Life on our planet spawned and lived its first years in the water. So our efforts to find extraterrestrial life have focused heavily on identifying planets with liquid water. However, a new study suggests that water may be much more abundant in the universe than we would expect. In fact, it could be a byproduct of the formation of any rocky planet.

Everywhere

“There are two hypotheses about the emergence of water. One is that it arrives on planets by accident, when asteroids containing water collide with the planet in question, “says Professor Martin Bizzarro of the Center for the Formation of Stars and Planets at the University of Health and Medical Sciences Faculty. Copenhagen.

“The other hypothesis is that water emerges in connection with the formation of the planet. Our study suggests that this hypothesis is correct and, if true, it is extremely exciting, because it means that the presence of water is a by-product of the planet’s formation process ”.

Together with assistant professor Zhengbin Deng, Bizzarro performed an analysis of a black meteorite known as “Black Beauty”. This meteorite is 4.45 billion years old and came to Earth from the original crust of Mars. As such, it contains a unique insight into the ancient history of the solar system. They explain that the results show that water may be much more common in the universe than we have assumed until now.

The duo found that Mars hosted water for the first 90 million years of its existence. This would have happened long before planets in the inner Solar System (such as Earth and Mars) were bombarded with water-rich asteroids, as per our previous hypothesis. In other words, it couldn’t have been the asteroids that sowed water on the planets (or, at least on Mars).

Black Beauty was first discovered in the Moroccan desert and soon hit the market, for around $ 10,000 per gram. The team raised the funds to purchase around 50 grams of the meteorite in 2017 and started working on it in the lab. They shattered and melted about 15 grams of meteorite and processed them with a new developed technique.

“We have developed a new technique that tells us that Mars in its infancy suffered one or more severe impacts with asteroids. The impact, Black Beauty reveals, created kinetic energy that released a lot of oxygen. And the only mechanism that could probably have caused the release of such large amounts of oxygen is the presence of water, ”says Zhengbin Deng.

“It suggests that water emerged with the formation of Mars. And it tells us that water can occur naturally on planets and does not require an external source like water-rich asteroids, ”adds Bizzaro.

The dry river and lake bed visible today on Mars are undeniable proof that the planet once harbored liquid water. However, its surface is quite cold, so the authors wanted to understand what it could be like. Their analysis suggests that the asteroid impacts likely released many greenhouse gases into its atmosphere. Their warming effect on the planet’s climate has led to conditions that allow liquid water to exist on its surface.

Moving forward, the team plans to examine the microscopic water-containing minerals in the asteroid, which have remained unchanged since their first formation.

The paper “Early oxidation of the Martian crust triggered by impacts” was published in the journal Advances in science.