Mercury’s ‘missing’ meteorites may have finally been found on Earth
Most meteorites who have reached Earth come from asteroid belt between March And Jupiter. But we have About 1,000 meteorites that comes from Moon and March. This is probably the result of asteroids striking their surfaces and ejecting equipment towards our planet.
He should also be physically possible so that such debris reach the land of MercuryAnother rocky body nearby. But so far, none has been confirmed as coming from there – presenting a longtime mystery.
A new study My colleagues and I discovered two meteorites who could have a mercurian origin. If it is confirmed, they would offer a rare window on the training and evolution of Mercury, potentially reshaping our understanding of the planet closest to Sun.
Because Mercury is so close to the sun, any space mission to recover a sample from there would be complex and costly. A naturally delivered fragment can therefore be the only practical means of studying directly its surface – which makes such such a invaluable discovery.
Observations of NASA messenger mission deduced the surface composition of the mercury. This suggests the presence of known minerals as such as sodium -rich plagioclases (like albite), pyroxene poor in iron (for example entertitis), olivine poor in iron (like flashes) and sulfur minerals such as oldhamite.
The meteorite North West Africa (NWA) 7325 was initially proposed as a possible fragment of mercury. However, its mineralogy includes rich in chrome pyroxene containing 1% iron. This does not correspond to the estimated surface composition of Mercury. Following this and other factors, this link was disputed.
In relation: Mercury can have a “potentially habitable” region below its surface, suggest salted glaciers
Aubrite meteorites have also been proposed as potential mercurian fragments. Recent modeling of their training suggests an origin of A large planetary body About 5,000 km in diameter (similar to mercury), potentially supporting this hypothesis.
Although the aubrites do not present chemical or spectral similarities (the study of the way in which light is divided by the wavelength) with the surface of Mercury, it was hypothetical that they can derive from the shallow coat of the planet (the layer below the surface). Despite the research in progress, the existence of a final meteorite of Mercury is not proven.
Our latest study studied the properties of two unusual meteorites, Ksar Ghilane 022 And North West Africa 15915. We found that the two samples seem to be linked, probably from the same parent body. Their mineralogy and surface composition also have intriguing similarities with the crust of mercury. This therefore prompted us to speculate on a possible Mercurian origin.
The two meteorites contain olivine and pyroxene, minor albitic plagioclases and the old. These characteristics are consistent with the predictions of Mercury’s surface composition. In addition, their oxygen compositions correspond to those of the Aubrite. These shared characteristics make the candidates convincing to be mercurian materials convincing.
However, notable differences exist. The two meteorites contain only traces of plagioclase, unlike the surface of Mercury, which is estimated at more than 37%. In addition, our study suggests that the age of samples has around 4,528 million years. This is significantly older than the oldest recognized surface units of mercury, which are planned (based on craters counting) to be approximately 4,000 million years.
If these meteorites come from mercury, they can represent an early material which is no longer preserved in the current surface geology of the planet.
Do we never stir?
To connect any meteorite to a specific asteroid type, the moon or the planet is extremely difficult. For example, the laboratory analysis of Apollo samples allowed meteorites found in desert collection shipments be matching Lunar materials. Martian meteorites have been identified By similarities between the composition of gases trapped in meteorites with measurements of the Martian atmosphere by the spaceship.
Until we visit Mercury and bring equipment, it will be extremely difficult to assess a meteorite plans link.
THE Bepicolombo spatial missionBy European and Japanese space agencies, is now in orbit around Mercury and is about to return high resolution data. This can help us determine the organism of ultimate origin for Ksar Ghilane 022 and North West Africa 15915.
If mercury meteorites were discovered, they could help resolve a variety of long -standing scientific questions. For example, they could reveal the age and evolution of the mercury crust, its mineralogical and geochemical composition and the nature of its gases.
The origin of these samples will probably remain a subject of continuous debate within the scientific community. Several presentations have already been planned for the next Meteoritic company meeting 2025 in Australia. We look forward to future discussions that will explore and further refine our understanding of their potential origin.
For the moment, all we can do is make educated assumptions. What do you think?
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