rock analysis. The asteroid provides insight into the evolution of the solar system.

A probe retrieved just 5 grams of the Ryugu asteroid at the end of 2020: Scientists now want to investigate the asteroid’s history – and the role of meteorites in the emergence of life on Earth.

Some time ago, a probe brought in material from the asteroid Ryugu — from which the research teams drew several conclusions: Organic molecules did indeed form in the cold cloud of gas and dust that once made up our solar system.

This material later interacted with liquid water inside the protoplanets, forming increasingly complex molecules – which may have ultimately helped create life on Earth.

Ryugu is an asteroid about 900 meters in diameter that orbits the Sun in a near-Earth orbit. This makes it a good target for space probes. Soil samples were brought to Earth by the Japanese Hayabusa-2 probe. Several research teams recently reported the results of their analyzes in a special issue of the journal Science.

Ryugu rock contains thousands of different organic molecules, including amino acids. From the exact frequency and structure, scientists have reconstructed the history of the small asteroid.

Ryugu is part of a larger body formed in the early days of the solar system and subsequently destroyed by a collision with another celestial body. According to the current state of knowledge, this original body was initially heated by radioactivity. This allowed liquid water to form and triggered chemical reactions that led to the formation of ever larger macromolecules.

As the analyzes showed, the temperature during these processes was about 40 degrees over several million years. Then Ryugu’s original body slowly cooled and froze – since then the organic molecules have remained virtually unchanged.

The researchers were particularly surprised that the same molecules had survived in samples from Ryugu’s surface for billions of years. Scientists see this as evidence of the thesis that meteorites enriched the young Earth with prebiotic organic substances and thus promoted the emergence of life.

sda/fi