Meteorites that crashed in Sudan ten years ago contained diamonds that could prove that protoplanet existed billion years before Earth, according to a study published Tuesday.
Researchers from Switzerland, France, and Germany analyzed diamonds inside the Almahata Sitta meteorite, which crashed in Sudan's Nubian Desert in October 2008. Based on their examination, they concluded that these diamonds were formed on a protoplanet whose size was between Mercury and Mars and exploded at least 4.5 billion years ago.
While it would seem that diamonds from space will differ from diamonds mined from the Earth's surface, they actually have major similarities. Most importantly, these similarities are further proof of the planetary embryo that remained theoretical up until now.
'Inclusions' And Physical Force Make Up Diamonds
The diamonds in the meteorite found in Sudan contain tiny crystals inside them that would have required immense pressure to form, according to the study published in the journal Nature. The scientists from the Ecole Polytechnique Fédérale De Lausanne calculated that only a pressure of 2.9 million psi would be able to form these diamonds.
The researchers mentioned that these tiny diamonds can form in three ways: enormous pressure shockwaves from high-density collisions between the meteorite parent body and other space objects, deposition by chemical vapor, or finally, the static pressure inside the parent body, like most diamonds are formed on Earth.
The scientists' analysis of the diamonds further revealed that they contain chromite, phosphate, and iron-nickel sulfides or what is scientifically referred to as "inclusions" of diamonds.
These inclusions also exist inside the diamonds that are mined from the Earth's surface.
The current study, however, is the first time that these inclusions were also identified in an extraterrestrial body or, in this case, diamonds from meteorites.
How Earth Diamonds Are Formed
Diamonds from Earth's surface can only crystallize at extremely high pressures. Specifically, they needed about 725,000 psi for a 3-fold diamond to form. The process requires a pure source of carbon for these gems to be created through geological processes.
Once pure carbon is trapped under the Earth's deepest layers, specifically at the great depth of about more than 150 kilometers down beneath a layer known as a mantle, diamonds are formed. Volcanic eruptions and tectonic movements push these formed diamonds into the Earth's surface, all the way to the area where they are usually mined by people.
Similarities Between Space Diamonds And Earth Diamond Support Theory Of Protoplanet
Before the current study, planetary formation models only predicted the presence of protoplanets that existed before the Solar System that people know today. Now, the scientists claim that the presence of these diamonds in the meteorite in Sudan offers compelling evidence that protoplanets indeed existed.
Farhang Nabiei, the lead author of the study and materials scientist, explains that for the diamonds in meteorites to have the same characteristic with that of Earth's diamonds, it means that they form inside an actual planet or, in this case, a protoplanet.
These protoplanets or planetary embryos are only lost now since they collided with other astronomical bodies like the one which birthed the moon, the study says. Some of them have collided with the sun or completely thrown out from the planetary axis, while others evolved to form larger planets at present.