Ancient Asteroid Provides Evidence of Amino Acid Precursors

SCIENTIFIC ACHIEVEMENT

Using the Advanced Light Source (ALS), researchers identified nitrogen-rich polymers in samples from the asteroid Bennu, revealing early chemical alterations in rocky bodies.

SIGNIFICANCE AND IMPACT

The results support the idea that asteroids, such as Bennu, may have carried water and the other chemical building blocks of life to Earth in the distant past.

Asteroid holds hidden secrets

In 2023, NASA returned material gathered from the 4.5-billion-year-old asteroid Bennu, which formed from minerals and ice in a primordial nebula. The rocks were gathered as part of NASA’s OSIRIS-REx mission, the first US mission to return samples from an asteroid. Lawrence Berkeley National Laboratory (Berkeley Lab) continues to participate in a series of multi-institutional research studies investigating Bennu’s chemical makeup to better understand how our solar system and planets evolved.

Past research on Bennu samples at Berkeley Lab’s ALS revealed that many minerals formed in watery environments. In the current study, the researchers rolled back the clock to examine a narrow period shortly after the asteroid formed but before it was exposed to the water that altered the chemical nature of the rock.

The researchers identified long chains of organic molecules, richer in nitrogen and oxygen than the previous samples. With this information, the team reconstructed the conditions during the earliest periods of the asteroid’s existence.

Read more on the ALS website

A star is born

Swiss Light Source SLS reveals complex chemistry inside ‘stellar nurseries’

An international team of researchers has uncovered what might be a critical step in the chemical evolution of molecules in cosmic “stellar nurseries.” In these vast clouds of cold gas and dust in space, trillions of molecules swirl together over millions of years. The collapse of these interstellar clouds eventually gives rise to young stars and planets.

Like human bodies, stellar nurseries contain a lot of organic molecules, which are made up mostly of carbon and hydrogen atoms. The group’s results, published in the journal Nature Astronomy, reveal how certain large organic molecules may form inside these clouds. It’s one tiny step in the eons-long chemical journey that carbon atoms undergo—forming in the hearts of dying stars, then becoming part of planets, living organisms on Earth and perhaps beyond.

“In these cold molecular clouds, you’re creating the first building blocks that will, in the end, form stars and planets,” said Jordy Bouwman, research associate at the Laboratory for Atmospheric and Space Physics (LASP) and assistant professor in the Department of Chemistry at University Colorado Boulder.

For the new study, Bouwman and his colleagues took a deep dive into one stellar nursery in particular: the Taurus Molecular Cloud (TMC-1). This region sits in the constellation Taurus and is roughly 440 light years (more than 2 quadrillion miles) from Earth. The chemically complex environment is an example of what astronomers call an “accreting starless core.” Its cloud has begun to collapse, but scientists haven’t yet detected embryonic stars emerging inside it.

Read more on the PSI website

Image: Using PEPICO spectroscopy at the SLS, researchers discovered how hexagonally-shaped ortho-benzyne molecules can combine with methyl radicals to form a series of larger organic molecules, each containing a ring of five carbon atoms.

Credit: Henry Cardwell