For many years, the prevailing hypothesis was that life emerged through “prebiotic chemistry,” the process by which organic compounds on Earth self-organized over time and eventually formed living organisms. But a study published in the journal Nature Astronomy offers a different view.

The prevailing theory faced a major problem: Earth’s surface rocks lacked reactive, soluble forms of key elements vital to life, such as phosphorus, sulfur, nitrogen and carbon.

Researchers say life on Earth faces intense competition for these scarce resources, and the mystery has deepened as scientists speculate about how life could have emerged in such limited conditions.

An old theory has new confirmation

It was previously believed that the materials needed for life had to come to Earth from space, but how these materials could survive the journey through Earth’s atmosphere remained unclear.

In their study, the scientists focused on cosmic dust, which is material created by collisions between asteroids or the breakup of comets. Unlike larger objects that are destroyed after entering Earth’s atmosphere, cosmic dust particles pass through more smoothly, preserving primitive elements that may be critical for life.

Space dust reaches Earth in a steady stream, and some of it passes through the atmosphere relatively unharmed.
– scientists write.

Although space dust seems like a plausible source of the materials needed to support life, it is often overlooked in prebiotic theories because it tends to spread over large areas, making it difficult to study in high concentrations.

But researchers say natural processes like wind, rivers and glaciers concentrate fine-grained materials, including space dust, in specific places like sand dunes, beaches and glacial deposits. Such a concentration of cosmic dust could create an ideal environment for the origin of life.

To investigate this possibility, the team used astrophysical simulations and geological models to estimate the amount and composition of cosmic dust that accumulated on Earth during the first 500 million years after the Moon collided with it, a period when collisions between celestial bodies were common in the Solar System.

Their models show that the amount of cosmic dust on the early Earth 100-10,000 times largerthan today.

Research results

The study found that space dust makes up only a small fraction of deep-sea sediments, and can make up more than 50% of sediments in deserts and glaciated regions. The highest concentrations (more than 80%) were found in environments such as cryoconite holes in glaciers, where melting ice collects space dust. These areas, along with preglacial lakes, may have provided a suitable environment for the early development of life.

The data casts doubt on the assumption that cosmic dust played a minor role in the origin of life. According to the researchers, environments rich in cosmic dust, such as cryoconite pits or glacial regions, may have supported the early chemical processes that led to the development of life on Earth.

This research opens up new ways to understand how life emerged and suggests that cosmic dust may be a critical ingredient in the recipe for life.