Recent research has brought us closer to understanding how the building blocks responsible for the origin of life on the planet appeared on Earth, and everyone here is reading this article right now. In conclusion? Scientists recently discovered that zinc found in meteorites and other “unmolten” asteroids, also known as planetesimals, holds the key to solving this mystery.

Volatile substances such as zinc bind

Volatile substances are substances that easily turn into gases at relatively low temperatures. Think of things like water, carbon dioxide, methane and ammonia. In planetary science, we often talk about volatile elements or low-boiling point compounds that play key roles in creating the atmosphere and oceans.

As planets form, they tend to trap these volatiles in rock or ice. Over time, heat and geological activity can release them, causing events such as volcanic eruptions and even contributing to the formation of the atmosphere.

The study of volatiles is extremely important for understanding planetary systems, including our own Earth. These substances can affect everything from climate to surface chemistry and are critical to the potential for life. That’s why when scientists look for signs of life on other planets, they also look for volatile substances; these are often associated with biological processes.

Bricks of life and zinc

Determining the origin of these volatile elements on Earth is no easy task. Yet our scientists are not afraid of a good secret. They found that the special composition of zinc unique to meteorites could help identify sources of volatile substances on Earth. Scientists investigating the complexity of our solar system have discovered that zinc on Earth has its own intriguing origin story.

“One of the most fundamental questions about the origin of life is where the materials needed for life to develop come from,” said Dr Rhyssa Martins from Cambridge’s Department of Earth Sciences.

“If we can understand how these materials got to Earth, it could give us clues about how life arose here and how it might have arisen elsewhere.”

It turns out that the answers to questions about the origin of life lie in zinc and the tiny objects that make up our rocky planets.

Role of planets

Planetesimals, compact objects formed through a process known as accretion, are the unsung heroes in the formation of rocky planets like ours. However, they are not all the same. The first planetoids exposed to high levels of radioactivity melted away, losing their valuable volatile materials.

However, some late-blooming planetesimals formed after the peak of radioactivity survived the melting process and thus retained their volatile elements.

In a published study Science DevelopmentsDr. Martins and his colleagues investigated different forms of zinc that came to Earth from these planets. Their research involved measuring the zinc content of a large sample of meteorites taken from various planets and tracing Earth’s accumulation path, a journey spanning tens of millions of years.

Zink’s story about the origin of life

Their findings are nothing short of fascinating. The molten planetesimals appeared to produce only 10% of the zinc, even though they make up about 70% of the Earth’s total mass.

Where did the rest come from? It appears that materials that do not melt and do not lose their volatile elements are rich in zinc. These unmelted or “primitive” materials were sources of volatile substances vital to the Earth.

“We know that the distance between a planet and its star is a determining factor in creating the conditions necessary for that planet to support liquid water on its surface,” said Martins, lead author of the study.

“But our results show that there is no guarantee that planets, whatever their physical state, contain the right materials to have enough water and other volatiles.”

Results of the study

The implications of this research are far-reaching. Understanding the movement of elements like zinc over millions or even billions of years could be a critical tool in the search for life elsewhere, such as Mars or planets outside our solar system.

“The role that these different materials play in providing volatiles is something we need to keep in mind as we search for habitable planets elsewhere,” Martins emphasized.

This research brings us closer to understanding the complex interplay of elements that gave rise to life on Earth. And ultimately, this may even lead us to the discovery of life in the vast expanses of space. This important research was supported in part by both Imperial College London and the European Research Council (ERC) and United Kingdom Research and Innovation (UKRI). The research was published in the journal. Science Developments.