Scientists baffled by discovery of unexpected mineral on asteroid Ryugu

India Today

17 hours ago

The discovery of these salt minerals has broader implications for understanding the role of water. (Photo: Nasa) Hayabusa2 returned samples from asteroid Ryugu providing new mineral insights
Djerfisherite found in Ryugu challenges previous formation assumptions
Mineral usually forms in reduced environments unlike Ryugu's known conditions
The rocks and soil samples from asteroid Ryugu have provided new insights into the nature of primitive asteroids and the formation of the Solar System.
A research team from Hiroshima University has identified the mineral djerfisherite, a potassium-containing iron-nickel sulfide, in a sample from this C-type asteroid. This discovery, published in Meteoritics & Planetary Science, challenges existing paradigms since djerfisherite was not expected to form under the conditions present on Ryugu.
"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," explained Masaaki Miyahara, the study's lead author. This unexpected presence raises questions about Ryugu's formation, suggesting either an unusual environment or a long-distance transport process early in the solar system's history.
The presence of djerfisherite suggests the possibility of mixed material formation histories in the early solar system, or that Ryugu experienced distinct, localised chemical conditions. "The discovery of djerfisherite in a Ryugu grain suggests that materials with very different formation histories may have mixed early in the solar system's evolution, or that Ryugu experienced localised, chemically heterogeneous conditions not previously recognised," Miyahara elaborated. A research team at Hiroshima University discovered the presence of the mineral djerfisherite. (Photo: Hiroshima University)
Ryugu, a part of a larger parent body formed between 1.8 and 2.9 million years after the solar system's beginning, originated in its outer regions.
This parent body contained water and carbon dioxide in ice form. Heating by radioactive decay melted the ice, which generally remained below 50C. This environment contrasts with enstatite chondrites, where djerfisherite is known to form from high-temperature gases.
Djerfisherite's formation could result from two processes: intrusion from another source during Ryugu's parent body's formation or intrinsic formation when Ryugu's temperature exceeded 350C. Preliminary evidence favours the intrinsic formation hypothesis, prompting further isotopic studies to explore the origins of this and other Ryugu grains.
The next research steps aim to reconstruct the early mixing processes and thermal histories of small bodies like Ryugu. "Ultimately, our goal is to reconstruct the early mixing processes and thermal histories that shaped small bodies like Ryugu, thereby improving our understanding of planetary formation and material transport in the early solar system," stated Miyahara.
This discovery not only challenges the current understanding of Ryugu's compositional uniformity but also opens new avenues for research into the complexity and formation of primitive asteroids, potentially reshaping longstanding theories about material transport in the early solar system.
The rocks and soil samples from asteroid Ryugu have provided new insights into the nature of primitive asteroids and the formation of the Solar System.
A research team from Hiroshima University has identified the mineral djerfisherite, a potassium-containing iron-nickel sulfide, in a sample from this C-type asteroid. This discovery, published in Meteoritics & Planetary Science, challenges existing paradigms since djerfisherite was not expected to form under the conditions present on Ryugu.
"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," explained Masaaki Miyahara, the study's lead author. This unexpected presence raises questions about Ryugu's formation, suggesting either an unusual environment or a long-distance transport process early in the solar system's history.
The presence of djerfisherite suggests the possibility of mixed material formation histories in the early solar system, or that Ryugu experienced distinct, localised chemical conditions. "The discovery of djerfisherite in a Ryugu grain suggests that materials with very different formation histories may have mixed early in the solar system's evolution, or that Ryugu experienced localised, chemically heterogeneous conditions not previously recognised," Miyahara elaborated. A research team at Hiroshima University discovered the presence of the mineral djerfisherite. (Photo: Hiroshima University)
Ryugu, a part of a larger parent body formed between 1.8 and 2.9 million years after the solar system's beginning, originated in its outer regions.
This parent body contained water and carbon dioxide in ice form. Heating by radioactive decay melted the ice, which generally remained below 50C. This environment contrasts with enstatite chondrites, where djerfisherite is known to form from high-temperature gases.
Djerfisherite's formation could result from two processes: intrusion from another source during Ryugu's parent body's formation or intrinsic formation when Ryugu's temperature exceeded 350C. Preliminary evidence favours the intrinsic formation hypothesis, prompting further isotopic studies to explore the origins of this and other Ryugu grains.
The next research steps aim to reconstruct the early mixing processes and thermal histories of small bodies like Ryugu. "Ultimately, our goal is to reconstruct the early mixing processes and thermal histories that shaped small bodies like Ryugu, thereby improving our understanding of planetary formation and material transport in the early solar system," stated Miyahara.
This discovery not only challenges the current understanding of Ryugu's compositional uniformity but also opens new avenues for research into the complexity and formation of primitive asteroids, potentially reshaping longstanding theories about material transport in the early solar system. Join our WhatsApp Channel