"This is the first compelling evidence for such a large body that has since disappeared", the authors wrote in the study. New research has shown that orality contain large diamond grains, which could occur when high pressure inside the protoplanet. The Almahitta Sitta is named after the location in Sudan above which the space rock exploded in 2008. The asteroid, now known as "2008 TC3", was just over four meters in diameter.
The Almahata Sitta meteorites are extremely interesting, as the specimens exhibit multiple distinct lithologies, ranging from ordinary chondrite to bencubinnite.
The crashing of the meteorite was witnessed by many in the town of Wadi Halfa and at a railway stop in the Nubian desert, known as "Station Six".
The Almahata Sitta fragments are ureilites, a kind of rocky meteorite containing clusters of tiny diamonds. Such a lot of diamonds could not appear during the compression of graphite under the influence of shock waves or chemical deposition from the gas rich in carbon.
The unanswered question, so far, has been the planetary origin of 2008 TC3 ureilites.
Researchers from Switzerland, France and Germany examined diamonds found inside the Almahata Sitta meteorite and concluded they were most likely formed by a proto-planet at least 4.55 billion years ago.
The researchers studied the diamond samples using a combination of advanced transmission electron microscopy techniques at EPFL's Interdisciplinary Centre for Electron Microscopy. The discovery marks the first time inclusions have been identified inside extraterrestrial diamonds.
They discovered chromite, phosphate and iron-nickel sulfide embedded in the diamond, with compositions and morphologies that could only have occurred under greater pressure than 20 gigapascals - almost 200,000 times that of sea level atmospheric pressure. Other of these went on to form larger planets, or collided with the Sun or were ejected from the solar system altogether. This level of internal pressure can only be explained if the planetary parent body was a Mercury- to Mars-sized planetary "embryo", depending on the layer in which the diamonds were formed.
A meteorite which crashed to Earth a decade ago has now been discovered to be part of the early solar system. Some of these bodies were almost as big as Mars and one of them, dubbed Theia, collided with Earth to throw our moon into orbit. "This study provides convincing evidence the ureilite parent body was one such large "lost" planet before it was destroyed by collisions".