The Makhonjwa Mountains situated in South Africa have few of the oldest rocks on Earth. However, all the rock constituents do not have Earth as their place of origin. Researchers have informed that they have detected traces of some extraterrestrial material which has been buried deep in the volcanic remains dating back to some 3.3 billion years ago. The old age of the mountain range provides useful information about Precambrian environment in which the evolution of life took place. The study has been reported in Geochimica et Cosmochimica Acta.
Frances Westall, an astrobiologist from CNRS Centre for Molecular Biophysics commented that this has been the first instance in which they have found actual tangible proof for extraterrestrial carbon present in the rocks. Earth has been impacted by violent meteorites from billions of years before which have led to major changes in the surface of the planet.
Several scientists hypothesize this far that the building blocks of life on Earth could be extraterrestrial molecules and the discovery in the Makhonjwa Mountains provides more support to this claim.
The volcanic deposit, Josefsdal Chert which lies within the Makhonjwa Mountains has a rock layer present in it bearing thickness of 2mm which has two “anomalous” signs in it. Taking the help of electron paramagnetic resonance spectroscopy, scientists have concluded that rock aging 3.3 billion years has two kinds of insoluble organic components, and both lead to extraterrestrial origins.
An EPR signal was similar to something scientists have seen before in carbonaceous chondrites: ancient meteorite samples which had organic compounds. This is the first instance where researchers have detected this. Several nano-materials of nickel, iron and chromium have also been identified in the rock samples, which are not usually detected in the rock formations of Earth. This suggests that they might have originated from some farther location in the universe.
Didier Gourier, a chemical engineer from PSL Research University explained that the formation of nickel-rich chrome spinels which are also termed as cosmic spinels takes place when extraterrestrial objects enter the atmosphere of the Earth.
The organic and spinel materials are supposedly contradictory in nature to exist at the same place in Josefsdal Chert. Scientists are not particularly sure regarding this explanation. The hydrogenated organic matter can only exist when the falling material’s temperature does not exceed that of a few hundred degrees. But, the cosmic spinels are formed only by the melting of an object when it enters Earth’s atmosphere.
Researchers have put forward a theory that micrometeorites might have mixed with the ash clouds and in the process of settling down on Earth, extraterrestrial carbon may have been preserved alongside cosmic spinels. Scientists are still exploring other possible causes of this phenomenon.