Sample from asteroid bennu rewrites the story of the origin of life

Scientists studying asteroid Bennu have discovered that key amino acids may have formed in icy, radiation-rich environments rather than warm water. The findings suggest life”s basic ingredients can arise in far more extreme corners of space than previously thought. (A view of eight sample trays containing the final material from asteroid Bennu.) Credit: NASA/Erika Blumenfeld & Joseph Aebersold

doi.org/10.1073/pnas.2517723123
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Scientists at Pennsylvania State University analyzed a small amount of dust collected from the asteroid Bennu, brought to Earth by NASA’s OSIRIS-REx mission in 2023, and reached a surprising conclusion that changes what was thought about how the basic components of life arose in space

The asteroid Bennu, about 4.6 billion years old, is a remnant of the early formation of the solar system, and its rocks contained amino acids, essential molecules that form proteins and participate in virtually all biological processes.

Until now, the most accepted idea was that these amino acids, such as glycine-the simplest of them, with only two carbon atoms-formed mainly in environments with hot liquid water, through a chemical process known as Strecker synthesis, which involves substances such as hydrogen cyanide, ammonia, and certain organic compounds reacting under moderate aqueous conditions.

This view linked the origin of these basic ingredients of life to scenarios similar to those of early Earth or to asteroids that underwent heating and showed the presence of water.

However, new research, published in February 2026 in the journal “Proceedings of the National Academy of Sciences,” shows that at least some amino acids from Bennu formed differently, under much more extreme conditions: extremely cold ice exposed to intense cosmic radiation in the outer regions of the young solar system.

The team examined isotopes-small variations in the mass of carbon and nitrogen atoms-present in glycine and other molecules from the tiny, teaspoon-sized sample using high-precision instruments.

The isotopic signatures found do not correspond to the traditional model of formation in hot water, but point to chemical pathways that occur in icy and irradiated environments.

This discovery is even more impactful when compared to that of another famous meteorite, Murchison, which fell in Australia in 1969 and also contains amino acids.

While Murchison’s asteroids exhibit isotopic patterns consistent with formation in liquid water and mild temperatures, those of Bennu reveal distinct chemical origins, suggesting that the progenitor bodies of these objects came from different regions of the early solar system.

Furthermore, researchers observed that mirror-image forms of certain amino acids, such as glutamic acid-which are chemically identical but with inverted molecular orientation-exhibit surprisingly different nitrogen signatures, something unexpected and indicating even greater diversity in formation processes.

Allison Baczynski, assistant professor of geosciences at Penn State and one of the lead authors of the study, explained that these results “completely changed the landscape” of what was thought about amino acid formation on asteroids.

Now, there appear to be many more ways and conditions for these building blocks of life to arise, not just in warm, liquid water.

Her colleague, postdoctoral researcher Ophélie McIntosh, highlighted that the very different isotopic patterns between Bennu and Murchison indicate that these asteroids formed in chemically distinct parts of the solar system, expanding the possibilities of how complex organic molecules could have reached early Earth through asteroid impacts.

This new discovery suggests that the ingredients necessary for life were even more common and varied in the early solar system than previously thought, possibly forming in hostile environments of ice and radiation, even before the existence of our planet.

Scientists say they now have more questions than answers and plan to analyze samples from other meteorites to investigate whether there is even greater diversity in these prebiotic chemical pathways.

The Bennu sample is opening doors to a better understanding of how the chemistry that led to the emergence of life may have spread throughout the cosmos.

Published in 02/15/2026 00h05

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Text adapted by AI (Grok) and translated via Google API in the English version. Images from public image libraries or credits in the caption. Information about DOI, author and institution can be found in the body of the article.

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