Rare Mineral Discovery Rewrites Asteroid History
A perplexing find within a Ryugu asteroid sample has scientists rethinking the evolution of our solar system. The discovery of djerfisherite, an unusual mineral, hints at complex origins and challenges current understanding of how primitive asteroids like Ryugu formed.
Unexpected Mineral in Asteroid Grain
The Hayabusa2 mission, which returned samples from asteroid Ryugu on December 6, 2020, continues to yield surprising insights. Researchers at **Hiroshima University** have identified djerfisherite, a rare iron-nickel sulfide, within a Ryugu grain, defying expectations about the asteroid’s composition.
The pristine samples from asteroid Ryugu returned by the Hayabusa2 mission on December 6, 2020, have been vital to improving our understanding of primitive asteroids and the formation of the Solar System.
— World Today News (@worldtodaynews) May 28, 2025
“Djerfisherite is a mineral that typically forms in very reduced environments, like those found in enstatite chondrites, and has never been reported in CI chondrites or other Ryugu grains,”
—Masaaki Miyahara, Associate Professor, Graduate School of Advanced Science and Engineering, Hiroshima University
This discovery opens new avenues of research into planetary formation, particularly in the early solar system. Analysis of meteorites helps scientists understand the building blocks of planets; approximately 50,000 meteorites have been found on Earth (The Planetary Society, 2024).
Formation Theories and Implications
The presence of djerfisherite in Ryugu grains presents a puzzle for scientists. The mineral typically forms in highly reduced environments, conditions not usually associated with the asteroid’s formation. This has led to two main hypotheses.
The first suggests the mineral arrived from another source during the formation of Ryugu’s parent body. Alternatively, it may have formed internally when the asteroid’s temperature rose above 350℃.
According to **Miyahara**, “This finding challenges the notion that Ryugu is compositionally uniform and opens new questions about the complexity of primitive asteroids.”
Next Steps
Further research will involve isotopic studies of the Ryugu grains. Scientists hope to reconstruct the mixing processes and thermal histories of objects like Ryugu to enhance understanding of material transport during the early solar system’s development.
