The crust in a urea stone found in Sudan is a mystery. It is speculated that two years ago, its origin can only be in a missing matrix in the solar system that is under high pressure and larger than Mercury. Now, Italian scientists have concluded that this precious substance can form asteroids.
Diamonds exist in rare meteorites Urea (Named after the Russian town Novy Urey where one of them fell) did not cause controversy among scientists.
One hypothesis is that these diamonds are formed in a similar way to diamonds on Earth: deep in the mantle, a large number of rocks stack together will generate the necessary high pressure.
If diamonds are born in this way, their parent body will be a large protoplanet, about the size of Mercury and Mars, which will support the existence of such large objects in the early solar system.
This was proposed by Swiss scientists in 2018 after analyzing meteorite samples Almahata Sitta, Is the suleite recovered from several fragments in the Nubian Desert (Sudan).his Learn It is pointed out that the composition and shape of the diamond element can only be explained when it is formed under a pressure greater than 20 gigapascals, which means that there are missing large planetary embryos.
Two samples from Almahata Sitta and one sample from NWA 7983
But now, another international team of scientists led by a professor Fabrizio Nestola From University of Padua (Italy), NASA, The other two samples of Almahata Sitta meteorite have been analyzed by electron microscopy, X-ray micro-diffraction and Raman spectroscopy, the other is called NWA 7983 – Established in Morocco in 2013 – and came to different conclusions.
Fragments of the NWA 7983 meteorite found in Morocco. /John Tanner
“Our results show that the formation of micron-sized and nano-sized diamonds found together in urea stone can be explained by’impact events’ (generated after clicking) on small objects. PlanetaryThere is no need to prolong the growth time between Mercury and Mars under high pressure,” the author emphasized that they published their work in the journal. NASA.
Micron and nanometer diamonds and metal iron and graphite (The most stable form of carbon, followed by diamond). This mineral structure is consistent with the diamond formed by the rapid transformation of graphite during impact and short-term impact events at a pressure as low as 15 GPa. The diamond formed is similar to the industrially catalyzed diamond production process.
According to the authors, the discovery that the formation of diamonds in urea stone does not require a Mars-sized matrix, which is of great significance to the planetary formation model and provides new data for studying the history of the solar system.
Black fragments of the Almahata Sitta meteorite found in the Nubian Desert of Sudan. / P.Jenniskens (SETI Research Institute/NASA Ames)
Fabrizio Nestola and others. “The cause of the impact of diamonds in meteorites”. NASA, September 28, 2020.