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Tryptophan Found on Asteroid Bennu: Life's Building Blocks from Space
27 Nov
Summary
- Tryptophan, an essential amino acid, was detected in samples from asteroid Bennu.
- NASA's OSIRIS-REx mission returned pristine samples from Bennu for analysis.
- The discovery supports the theory that asteroids may have delivered life's ingredients to Earth.

NASA's OSIRIS-REx mission has successfully identified tryptophan, a vital amino acid, within samples retrieved from the asteroid Bennu. This marks a significant milestone as it's the first detection of this particular amino acid in any extraterrestrial sample, expanding the known repertoire of life's building blocks originating from space. The pristine nature of the Bennu samples, returned to Earth in 2023, is crucial for this finding, as it bypasses the chemical alterations that meteorites undergo during atmospheric entry.
The analysis of Bennu's composition offers insights into the early solar system's chemistry, dating back approximately 4.5 billion years. Previously, 14 other protein-building amino acids and biological nucleobases were found in these samples, reinforcing the idea that asteroids could have delivered essential organic molecules to early Earth. This latest discovery of tryptophan, one of the more complex amino acids, further strengthens the hypothesis that the fundamental components for life were readily available in the early solar system.
Scientists emphasize that while asteroids like Bennu provide the necessary "jigsaw pieces" for life, they do not contain life itself. The OSIRIS-REx mission's success in returning uncontaminated samples is paramount for understanding the complex chemistry that predated life on Earth. This ongoing research continues to shed light on the potential extraterrestrial origins of life's fundamental ingredients.




