The initial bodies that formed in the solar system gathered materials from stars, presolar molecular clouds, and protozoan debris. Asteroids that have not experienced planetary differentiation retain evidence of these significant materials. Nevertheless, geological processes such as hydrothermal changes can significantly modify their composition and chemistry. In a recent study, researchers scrutinized the elemental and isotopic composition of samples from the asteroid Bennu, uncovering the origin and nature of the materials associated with its parent body.
This mosaic image of the asteroid Bennu consists of 12 images collected on December 2, 2018 by a 15-mile (24 km) Polycam instrument at Osiris-Rex. Image credit: NASA/NASA’s Goddard Space Flight Center/University of Arizona.
“Our analysis shows that Bennu’s elemental composition closely resembles that of the sun,” stated LLNL scientist Greg Brennecka.
“This indicates that the materials obtained from Bennu provide a valuable reference to the initial arrangement of the entire solar system.”
“Notably, Bennu has remained largely untouched by intense heat, which would alter some of its original ingredients.”
Researchers continue to investigate how planets form, and determining the initial composition of the solar system is akin to gathering a recipe for a cake.
“With that recipe, we gain insight into how all these elements interacted to create the solar system and, ultimately, the Earth and its living beings,” Dr. Brennecca remarked.
“If we aim to understand our origins, the composition of our solar system serves as a fundamental starting point.”
Outer view of the Osiris-Rex sample collector. Sample material for the asteroid can be seen in the center right. Image credits: NASA/Erika Blumenfeld/Joseph Aebersold.
The Osiris-Rex mission by NASA has introduced new possibilities by returning pristine samples to Earth while avoiding contamination from our planet.
LLNL scientist Quinn Shollenberger commented:
“We cannot tackle the significant question of ‘origins’ without a sample on Earth.”
“One of our objectives is to ascertain which elements of the periodic table and their percentages contributed to the solar system’s inception. Bennu can help us uncover this,” noted LLNL scientist Jan Render.
To achieve these findings, researchers ground the asteroid material into fine powders and dissolved them in acid.
This mixture was then analyzed with a series of mass spectrometers to determine the concentrations of most elements within the periodic table.
From these results, scientists have sorted the samples by elements and successfully analyzed the isotopic ratios of several.
“I work at a National Laboratory that boasts remarkable analytical capabilities with state-of-the-art equipment,” shared LLNL scientist Josh Winpenny.
“It is quite rare to have all these functions consolidated in one place, allowing us to make optimal use of these valuable materials.”
“NASA’s Johnson Space Center researcher Dr. Anne Nuguen stated:
“We discovered stardust grains with compositions predating our solar system, organic materials likely formed in interstellar space, and high-temperature minerals that originated close to the sun.”
“All these components were transported over to the region that formed Bennu’s precursor asteroids.”
Survey results published in the journal Natural Astronomy.
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JJ Burns et al. Diversity and origin of materials accumulated by Bennu’s pro-asteroids. Nat Astron Published online on August 22, 2025. doi:10.1038/s41550-025-02631-6
Source: www.sci.news
