Life-Building Organic Molecules Found in Samples from Asteroid Ryugu


2023-03-02 17:08:35

A sample of material collected from the asteroid Ryugu. (Image credit: JAXA)

A sample of material collected from the asteroid Ryugu. (Image credit: JAXA)

The asteroid Ryugu is rich in organic molecules that could serve as the building blocks of life. The discovery was made when scientists took a first look at a sample collected by the Hayabusa2 spacecraft from the asteroid. 

The Ryugu sample contains several so-called "prebiotic organics" including several types of amino acids that are used by living things to build proteins essential for regulating chemical reactions and forming structures like hair and muscles. These molecules can also be created by various non-living processes, such as chemical reactions that can take place in asteroids.

The findings add more credibility to the theory that the basic ingredients needed to kickstart the development of life on Earth could have been delivered to the planet in its infancy from space.

The presence of prebiotic molecules on the asteroid surface despite its harsh environment caused by solar heating and ultraviolet irradiation, as well as cosmic-ray irradiation under high-vacuum conditions, suggests that the uppermost surface grains of Ryugu have the potential to protect organic molecules. These molecules can be transported throughout the solar system, potentially dispersing as interplanetary dust particles after being ejected from the uppermost layer of the asteroid by impacts or other causes.

The term "organic molecules" describes a wide range of compounds containing the element carbon coupled with hydrogen, oxygen, nitrogen, sulfur and other atoms and are the building blocks of all forms of life here on Earth.

These compounds can be created by chemical reactions that don't involve living things, meaning that chemical processes within asteroids can create the ingredients for life. The search for these chemical processes that could have led to the emergence of life on Earth is known as "prebiotic chemistry." 

Also found in the Ryugu sample were organic prebiotic molecules that form in presence of liquid water, another vital ingredient for life, like aliphatic amines, carboxylic acids, polycyclic aromatic hydrocarbons, and nitrogen-containing heterocyclic compounds.

Source: Space .com