The US Space Agency discovers key life building blocks in asteroid samples

NASA’s OSIRIS-REx spacecraft launched in 2016 brought from there what everyone believed, mud and rocks! The spacecraft had however dug out the very building blocks of life from the asteroid material. Going by the name of Bennu, the asteroid rocks and dust brought on earth in 2023, many organic molecules were discovered in it.

The evidence of life wasn’t found on Bennu, rather it strengthened the theory of widespread abundance of life on other solar system worlds. The theory of asteroids crashing into Earth and planting necessary ingredients on it for life to take hold has a greater chance of the same event happening on the other planets and moons.

The asteroid was formed during the early phases of solar system formation, in the first 10 million years and is about 4.5 billion years old. Scientists brought forth some important insights in 2023 which included traces of carbon and water locked up in clay minerals.

A thorough analysis of the Bennu samples through two new studies is the first one done so far. Despite significant findings from the samples, more studies need to be conducted to find the exact reasons behind the emergence of life on planets. And also, why other planetary bodies are excluded from them.

In 2010, the Hayabusa mission from Japan brought a few micrograms of material from another asteroid, Itokawa. Hayabusa2 soon followed in 2020 and was also able to bring only a small quantity of the material from asteroid Ryugu. In the backdrop of these two missions, NASA was the first one to bring the asteroid material.

The absence of atmospheric contact helped NASA

The fact behind the significance of the NASA mission lies in the uncontaminated condition of the material due to the absence of atmospheric contact. In the second scenario, the meteorites undergo just that and are, in turn, contaminated by the conditions of the earth affecting the scientific results on a large scale.

Directly gathering material from the asteroid, like the NASA mission, is akin to looking into the early origins and thereby, conditions of life in the solar system. Organic molecules and amino acids necessary for the formation of life have been detected in the meteorites before but were found to be contaminated due to coming in contact with the earth’s atmosphere.

The associate administrator of NASA’s Science Mission Directorate, Nicky Fox said in a news briefing on Wednesday, “The OSIRIS-REx mission is already rewriting the textbook on what we understand about the ingredients thought to be necessary for the emergence of life in our solar system.”

Danny Glavin, an astrobiologist at NASA’s Goddard Space Flight Center confirmed the results by saying, “What’s so significant about the OSIRIS-REx Bennu findings is that those samples are pristine.” He again said, “The bottom line is: We have a higher confidence that the organic material we’re seeing in these samples is extraterrestrial and not contamination,” he said. “We can trust these results.”

Glavin also added that the Bennu samples were shielded from harsh conditions during atmospheric re-entry in a return canister. The samples were found to contain four nucleobases, which are the main components of DNA, RNA and thousands of organic compounds.

The nucleobases store and transmit genetic information and blueprints in the body cells. The findings published in the journal Nature have shown about 14 out of 20 amino acids utilized in the formation of proteins on the earth, in the sample studies.

Around 11 minerals were found in the briny mixture which was left out, after the water deposits evaporated on Bennu and another bigger asteroid. This is thought to be a significant find and another fact came to fore from the study.

The second fact according to Tim McCoy, curator of meteorites at the Smithsonian Natural History Museum in Washington, D.C., and a co-author of both studies, is the presence of salty crystals.

These crystals, he says, have been left after the water evaporation and are just like the sodium-rich crusts found in the dry lakebeds on the earth. An apt instance of that can be cited in Searles Lake in California.

McCoy in a statement said, “We now know from Bennu that the raw ingredients of life were combining in really interesting and complex ways on Bennu’s parent body.” Again, he said, “We have discovered that next step on a pathway to life.”

Amongst other equally important insights, the Bennu samples were found to contain exceptionally high concentrations of ammonia, which according to Glavin are, “about 100 times more than the natural levels of ammonia that you find in soils on the Earth.”

The key building block in the formation of Amino acids is ammonia, apart from being an essential ingredient in many biological processes. The next step following the formation of ammonia is the production of long-chain links in the formation of proteins.

The material found on other planetary bodies, Saturnian moon Enceladus and Ceres the small planet, is also surprising. Sodium carbonate compounds such as trona (sometimes referred to as “soda ash”) have been detected in the briny mixtures from the samples collected. The presence of the minerals has been detected for the first time and was never seen before in other extra-terrestrial samples.  

Pondering the earth-like conditions on the asteroid Bennu, researchers are wondering about that key difference in the creation of life on the asteroid itself.  Jason Dworkin, an OSIRIS-REx project scientist at NASA’s Goddard Space Flight Center said, “What did Bennu not have that Earth did have?”

He added, “This is a future area of study for astrobiologists around the world to ponder, looking at Bennu as an example of a place that had all the stuff but didn’t make life. Why was Earth special?”