Scientists question the impact of comets on the origin of life on Earth

Comets could hardly deliver to Earth the substances necessary for the emergence of life, found scientists at the University of Cambridge. The study is published in the journal Scientific Reports.

Using computer simulations, the researchers found that comets entered the Earth’s atmosphere at too high a speed and at too high an angle. Because of this, organic molecules had almost no chance to survive in a collision with the surface of the planet.

The scientists focused on hydrogen cyanide (HCN), which may have been involved in the origin of life. The simulations showed that even when these molecules were preserved, the probability of their accumulation in sufficient concentration was extremely low.

“It really had to be a one-in-a-million-probability event, as it required not only a collision at the right speed and at the right angle, but also the necessary concentration of substances, as well as the rapid development of chemical processes,” said lead author Richard Enslow.

According to scientists, the molecules necessary for the emergence of life could be formed as a result of the fall of asteroids or chemical processes on Earth itself.

The researchers also found that on Mars, the probability of delivery and preservation of organic molecules by comets was slightly higher due to the smaller size of the planet and a more sparse atmosphere. However, such a scenario is unlikely.

In February 2026, NASA reported the discovery of organic molecules, including methanol, cyanide and methane, in the gas-dust shell of interstellar comet 3I/ATLAS. They were recorded by the SPHEREx space telescope. Such substances are involved in biological processes on Earth, but can be formed without the participation of living organisms.