A decade ago, an astronomer in Arizona discovered an asteroid that was directed straight to the ground. He promptly called for help from colleagues and vacant stargazers who traced the space stone as it exploded in the sky and rained shrapnel down on the Nubian desert in Sudan. Students from the University of Khartoum volunteers to search for fragments, ultimately recover more than 600 parts of the meteorite now known as Almahata Sitta. It was the first time researchers ever traced an asteroid in the sky to a rock that they could hold in their hands.
But it's not even the coolest with Almahata Sitta. Not close.
A new study published in the journal Nature Communications reports that the meteorite contains small diamonds ̵
"These samples come from a time that we have no access to," said Farhang Nabiei, a material researcher at the Swiss Federal Institute of Lausanne and the author of the new report. The diamonds with the Almahata Sitta Meteorite were formed during a transitional solar system, When dust and gas swirled around the sun were brought together into planetary embryos, then grown to planets.
"And we're part of planets," said Nabiei. "This is part of the story of how we came to. "
Almahata Sitta belongs to a class of rocks called ureilites. They are partially differentiated – not made of primitive material that formed solstice but also not as mixed and baked as stones coming from modern planets . Unlike other meteorites, which can be traced to parenting like asteroids, Mars or the Moon by comparing the relationships between different varieties of elements, d has These stones are no known source.
And they always contain small spots of diamond.
Since the crystals are so small – less than a fraction of one percent of an inch in diameter – many researchers assumed that they were formed when graphite (an alternative form of carbon) was "shocked" by a collision with another body. But Nabiei and his colleagues noticed that the diamonds in Almahata Sitta were orders of magnitude greater than those caused by a shock event. They suspect that these crystals may have formed the same way that diamonds do on earth – under the incredibly high temperatures and pressures found in the interior of a planet – and then only broken by a shock wave in smaller fragments.
"Then this opens a whole new idea," said Nabiei. Diamond is so strong it acts as a powerful protective package for all that is fixed inside. It's nature's security range that can keep samples for billions of years.
"I thought that if there were diamonds formed inside a planet inside a parent's body, they could capture some material from their environment, "said Nabiei. He laughed." And they did. "
The impurities caught in The Almahata Sitta Diamonds – Crystal of Chromite, Phosphate and Iron Nickel Sulphide – are the first to be discovered in an alien diamond. They could only have formed under incredible pressure – equivalent to diving 600 kilometers into the earth's interior or attempt to hold 100,000 tons With your naked hands.
To create these conditions, Nabiei's meteorite's parent said the body would have been a planet at least as big as mercury and possibly as big as possible Like Mars.
What happened to this lost world? Nabiei can not say for sure. Many scientists believe that the early inner solar system was crowded with the big protoplanes that pulled and tugged into each other's lanes until they finally crashed, coalesced or decomposed. By the end of the time, about 100 million years after the birth of the solar system, only the four current ground plan remained.
Nabiei believes it is likely that all ureilites come from the same parent body, a protoplanet that lasted only a few million years before it was destroyed in a collision. He plans to search similar meteorites and search for inclusions that can give clues about their origins.