Japanese scientists have obtained new evidence supporting the hypothesis that life on Earth may have originated from the delivery of organic compounds by asteroids. By studying rock samples brought back from asteroid Ryugu, researchers discovered all the essential nitrogenous bases necessary for the formation of DNA and RNA—uracil, adenine, guanine, cytosine, and thymine.
This is reported by Finway
Japanese Scientists’ Discovery: Details of the Hayabusa-2 Mission
In 2020, the Hayabusa-2 spacecraft successfully delivered samples from asteroid Ryugu, which has a diameter of about 900 meters, back to Earth. Analysis of these samples revealed the presence of all five key nitrogenous bases that make up DNA and RNA. Previously, uracil—one of the RNA bases—had already been found in materials from Ryugu.
DNA serves as the genetic blueprint, while RNA acts as the main intermediary for translating genetic instructions into action. The detection of all bases in the asteroid samples indicates that such building blocks of life could have been brought to our planet by cosmic objects.
Widespread Presence of Life’s Building Blocks in the Solar System
Scientists emphasize that the presence of DNA and RNA components in the asteroid does not imply the existence of life on Ryugu itself. However, it suggests that asteroids may preserve molecules necessary for the chemical processes that led to the emergence of life on Earth. Similar compounds have also been found in materials from asteroid Bennu, confirming their widespread presence in the Solar System.
“The presence of RNA and DNA building blocks in an asteroid that has existed for billions of years indicates that asteroids could create and store molecules necessary for the chemical processes related to the origin of life on Earth.”
The authors of the study also note that nitrogenous bases have been found in meteorites that previously fell to Earth. When comparing different space rocks, it was established that the quantity of bases varies depending on the object’s history, and there is a correlation between the ratio of nitrogenous bases and the concentration of ammonia.
No known mechanisms for the formation of organic molecules account for such a connection, which may indicate the existence of an as-yet-unknown process for forming DNA and RNA bases in the early Solar System.
Previously, minerals older than the Earth itself were found in samples from asteroid Ryugu, and new software capable of teaching robots to play tennis and compete with humans was also discovered.