Breakthrough Discovery: Meteorites Potentially Originating from Mercury

In a groundbreaking revelation, scientists have identified two meteorites that may have originated from Mercury, the innermost planet of our solar system. This discovery, published on June 27, 2025, could provide invaluable insights into Mercury's composition and geological history, which have long eluded researchers due to the planet's challenging accessibility.

Mercury, located perilously close to the Sun, presents significant challenges for space missions. According to Dr. Johannes Benkhoff, Project Scientist for the BepiColombo mission, the journey to Mercury necessitates multiple planetary flybys to reduce speed against the Sun's gravitational pull. "To reach Mercury, you need to perform multiple such planetary flybys, and so the journey takes a long time," Dr. Benkhoff noted, highlighting the extraordinary energy requirements for exploration.

Meteorites, akin to those from Mars and the Moon, can be ejected from Mercury during impact events. Until now, scientists had speculated about the existence of Mercury meteorites, but no confirmed specimens had been identified. The recent study focuses on two unusual meteorites, Ksar Ghilane 022 and Northwest Africa 15915, which exhibit mineralogical characteristics suggesting a Mercurian origin. Dr. Ben Rider-Stokes, a Postdoctoral Researcher in Achondrite Meteorites at The Open University, emphasized that these meteorites contain minerals such as olivine and pyroxene that share intriguing similarities with Mercury's crust.

However, the findings are not without their challenges. The meteorites contain only trace amounts of plagioclase, a mineral expected to comprise a significant portion of Mercury’s surface. Estimates suggest that Mercury's surface holds over 37% plagioclase, while these meteorites show a minor presence of this mineral. Additionally, the meteorites are dated at approximately 4.528 billion years old, which is older than the estimated age of Mercury's surface, believed to be around 4 to 4.1 billion years. Dr. Simone Marchi, a planetary scientist with the NASA Lunar Science Institute, expressed the implications of this age discrepancy, stating, "If the oldest surface visible on Mercury is 4 billion or 4.1 billion years old, then that would imply that the first perhaps 500 million or 400 million years of the planet have been erased."

The findings imply that these meteorites might represent primordial materials from Mercury that have since been lost from the planet's surface, providing a potential window into the early history of our solar system's smallest planet.

While the study presents exciting possibilities, researchers caution that further investigation is required to confirm the meteorites' origin. The BepiColombo mission, set to enter Mercury's orbit in 2026, will conduct a detailed analysis of the planet's surface composition, which may help establish the connection between these meteorites and Mercury. As the authors of the study conclude, the upcoming mission promises to enhance our understanding of Mercury and could soon unravel the mysteries surrounding these intriguing meteorites, paving the way for a deeper exploration of the solar system's innermost planet.