Asteroid Bennu Sample Reveals Amino Acids Formed in Space Ice

Penn State scientists say Bennu's glycine may have formed in frozen, irradiated ice, not warm water, reshaping origins-of-life ideas.

Published on Feb. 10, 2026

Got story updates? Submit your updates here. ›

Penn State researchers studied amino acids in material from the asteroid Bennu and found that the amino acids, including the simplest one, glycine, likely formed in frozen, irradiated ice in the early solar system rather than in warm water on the asteroid. This challenges the prevailing theory that amino acids form in mild, watery conditions inside asteroids and suggests there are more diverse pathways for the formation of the building blocks of life.

Why it matters

This discovery reshapes our understanding of how the basic ingredients for life can form, suggesting they may arise in a wider range of conditions than previously thought, including in the frozen, irradiated environments of deep space. It also provides new insights that could guide future sample-return missions to study the origins of life.

The details

The Penn State team, led by geoscientist Allison Baczynski and postdoctoral researcher Ophélie McIntosh, analyzed a tiny sample of material from the asteroid Bennu returned by NASA's OSIRIS-REx mission. Using highly sensitive instruments, they measured the isotopes of amino acids in the sample, including glycine, the simplest amino acid. They found that Bennu's amino acids had very different isotopic signatures compared to those found in the Murchison meteorite, suggesting they formed in chemically distinct regions of the solar system. The team believes the amino acids in Bennu likely formed through "ice photochemistry" - chemical reactions in frozen, irradiated ice - rather than the previously proposed "Strecker synthesis" in liquid water.

  • In 2023, NASA's OSIRIS-REx mission delivered the Bennu sample to Earth.
  • The Penn State study was published in the Proceedings of the National Academy of Sciences in 2026.

The players

Allison Baczynski

An assistant research professor of geosciences at Penn State and co-lead author on the paper.

Ophélie McIntosh

A postdoctoral researcher in Penn State's Department of Geosciences and co-lead author on the paper.

Christopher House

A professor of geosciences at Penn State and co-author on the paper.

Katherine Freeman

An Evan Pugh University Professor of Geosciences at Penn State and co-author on the paper.

Mila Matney

A doctoral candidate in geosciences at Penn State and co-author on the paper.

Got photos? Submit your photos here. ›

What they’re saying

“Our results flip the script on how we have typically thought amino acids formed in asteroids. It now looks like there are many conditions where these building blocks of life can form, not just when there's warm liquid water.”

— Allison Baczynski, Assistant research professor of geosciences at Penn State (Proceedings of the National Academy of Sciences)

“One of the reasons why amino acids are so important is because we think that they played a big role in how life started on Earth. What's a real surprise is that the amino acids in Bennu show a much different isotopic pattern than those in Murchison, and these results suggest that Bennu and Murchison's parent bodies likely originated in chemically distinct regions of the solar system.”

— Ophélie McIntosh, Postdoctoral researcher in Penn State's Department of Geosciences (Proceedings of the National Academy of Sciences)

What’s next

The team plans to measure the carbon isotope value of formaldehyde in the Bennu sample to further investigate the potential role of Strecker synthesis in the formation of the amino acids. They also hope to analyze a range of different meteorites to look for more diversity in the conditions and pathways that can create the building blocks of life.

The takeaway

This study suggests that the basic ingredients for life may form in a wider range of environments than previously thought, including in the frozen, irradiated regions of deep space. It challenges the prevailing theory that amino acids require warm, watery conditions to form and opens up new possibilities for where the building blocks of life could arise in the universe.