Almahata Sitta was found by an automated telescope atop Mount Lemmon in Arizona, in October 2008. Researchers monitored it closely as it entered the atmosphere and exploded 37 km above North Sudan's Nubian desert. A report by the Arizona State University notes that about 4 kg of the meteorite, in the form of 280 small, thinly-crusted stones, each between 1 and 10 cm, was recovered during expeditions led by the University of Khartoum.
Diamonds found on the meteorite were small and irregular, notes a report by Popular Science. The specks of material trapped inside the heavy-duty diamond packaging allowed scientists to unravel a lot of information about its origin. The asteroid that burned up over Sudan was likely the remnant of an ancient planet that was born during the early years of the Solar System, but just could not keep up with the violent nature of planet formation.
The material inside the diamonds could be what the report calls a planetary embryo, which got violently obliterated before it got the chance to become anything. Also, the only way that any material can get trapped inside a diamond, says one of the researchers, is if it goes through immense levels of stress and pressure.
Also, the diamonds would have formed deep within whatever planet it was from, notes the report. This particular set of diamonds were formed at 20 gigapascals – the entire weight of its home planet pushing down on it. The planet would have been about the size of between Mercury and Mars.
However, the materials that made up the Almahata Sitta were neither from Mercury or Mars, says the report. It has been classified as a ureilite, mysterious rocks that do not match any rock that have so far been found or recorded.