An image of our planet and space. Depositphotos.

Scientists Find Further Evidence That Life May Have Been “Seeded” On Earth

This discovery supports the idea that C-type asteroids could be suppliers of prebiotic compounds to the young Earth. The report on the results of the work was presented at the 53rd Lunar and Planetary Science Conference (LPSC).

Planetary scientists working with soil samples from the asteroid Ryugu, delivered to Earth by the Hayabusa2 interplanetary station, have published new data. More than ten types of amino acids have been found in the soil, as well as polycyclic aromatic hydrocarbons and nitrogen compounds.

This discovery supports the idea that C-type asteroids could be suppliers of prebiotic compounds to the young Earth. The report on the results of the work was presented at the 53rd Lunar and Planetary Science Conference (LPSC).


Asteroid Ryugu and C-type bodies

Asteroid (162173) Ryugu belongs to the C-type. These bodies are characterized by low albedo, are found mainly in the Main belt located between Mars and Jupiter, and are considered parent bodies of carbonaceous meteorites.

Such meteorites, in turn, often contain various organic substances, including prebiotic compounds such as amino acids. Thus, C-type asteroids could deliver prebiotic organic molecules necessary for the emergence of life to the young Earth in the distant past.

In order to comprehensively study the substance of C-type asteroids, it is necessary to deliver it to terrestrial laboratories, for which the Japanese interplanetary station Hayabusa-2 went into space in 2014.

A picture of Ryugu taken by the station immediately after turning on the engines. Credit: JAXA
A picture of Ryugu taken by the station immediately after turning on the engines. Credit: JAXA

The Hayabusa2 Mission

The automatic interplanetary station Hayabusa2 was launched into space using an H-IIA launch vehicle on December 3, 2014. The device covered a total of 3.2 billion kilometers and entered orbit around the 500-meter near-Earth asteroid (162173) Ryugu on June 27, 2018.

For a year and a half of research, the station was able to obtain samples of the asteroid’s substance both from its surface and from the inner layers.

The station landed two small MINERVA-II-1 probes on the asteroid, the MINERVA-II2 module, as well as a large MASCOT (Mobile Asteroid Surface Scout) lander, which received valuable scientific data. The station itself managed to map the asteroid and comprehensively explore it.

Pebbles and boulders on the Surface of Ryugu. Credit: S. Tachibana/Science, 2022
Pebbles and boulders on the surface of Ryugu. Credit: S. Tachibana/Science, 2022

New results from asteroid Ryugu’s soil samples

A group of planetary scientists and members of the Hayabusa2 research group, led by Hiroshi Naraoka from Kyushu University in Japan, published the results of a search for organic compounds in Ryugu soil samples brought to Earth.

The aim of the research was a sample weighing 17.15 milligrams, collected from the surface of an asteroid, which was studied by various methods of mass spectrometry and mass spectroscopy.

What did the Ryugu samples contain?

The sample contained 3.76 mass fractions of carbon, 1.14 mass fractions of hydrogen, and 0.16 mass fractions of nitrogen, which means that Ryugu is richer in these elements compared to various types of carbonaceous chondrites. An enrichment in heavy isotopes of hydrogen and nitrogen is observed, which is similar to CI-type chondrites.

Microscopic images of Ryugu particles delivered to Earth. Particles with the letter A were taken from the surface of Ryugu, with the letter C - from the soil ejected from the crater. Credit: S. Tachibana et al. / Science, 2022
Microscopic images of Ryugu particles delivered to Earth. Particles with the letter A were taken from the surface of Ryugu, with the letter C – from the soil ejected from the crater. Credit: S. Tachibana et al. / Science, 2022

More than ten types of amino acids have been found, including proteinogenic amino acids such as glycine, D, L-alanine, as well as non-proteinogenic amino acids, including b-alanine and D, La-aminobutyric acid. Polycyclic aromatic hydrocarbons and various nitrogen compounds were also found in the samples.

The scientists concluded that Ryugu’s substance contains a surprisingly large variety of organic compounds of extraterrestrial abiogenic origin and has been exposed to water but not to high temperatures in the past.


Join the discussion and participate in awesome giveaways in our mobile Telegram group. Join Curiosmos on Telegram Today. t.me/Curiosmos


Sources:

Naraoka, H., Takano, Y., & Dworkin, J. P. (n.d.). SOLUBLE ORGANIC COMPOUNDS IN ASTEROID 162173 RYUGU. 53rd Lunar and Planetary Science Conference (2022).
Pultarova, T. (2022, March 9). Pristine asteroid Ryugu contains amino acids that are building blocks of life. Space.com.

Written by Vladislav Tchakarov

Hello, my name is Vladislav and I am glad to have you here on Curiosmos. As a history student, I have a strong passion for history and science, and the opportunity to research and write in this field on a daily basis is a dream come true.

Write for us

We’re always looking for new guest authors and we welcome individual bloggers to contribute high-quality guest posts.

Get In Touch