Diamonds found in an unknown meteorite came from a lost planet

An illustration of the early solar system when the planet body of the Almahata Sitta meteorite may have existed

A meteorite which crashed to Earth a decade ago has now been discovered to be part of the early solar system. Many planetary embryos were Mars-sized bodies, such as the one that collided with Earth to give rise to the Moon.

The Almahata Sitta exploded 23 miles above Sudan on October 7, 2008.

The asteroid, now known as "2008 TC3", was just over four metres in diameter and fell in the Nubian desert in Sudan.

Calculations of the pressure needed to form such diamonds pointed to the mystery planet being at least the same size as Mercury, or possibly Mars. Because diamonds are forged at vast pressures and temperatures, typically deep inside the planet, the various materials that get trapped inside are quite hard to get a hold of at the surface - and diamonds can preserve them for billions of years. Their remains make up the planets of today's solar system, along with asteroids and other rocky debris.

In the space rocks, which are also called meteorites, researchers found compounds common to diamonds on Earth, such as chromite, phosphate and iron-nickel sulfides. This is an extremely high form of pressure that humans can generate with certain explosives. 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.

The team of scientists studying its interior found both graphite and diamonds and discovered that the latter contained crystals that are only formed under extreme pressure conditions-scientists estimated it would take around 200,000 bars, or 2.9 million pounds per square inch (psi) to create them. But at first, the origins of the diamonds eluded researchers. Numerous rare meteorites contained nano-sized diamonds.

Now, a new study published in the journal Nature Communications supports that idea.

Using an advanced technology called transmission electron microscopy the scientists scanned some of the larger diamonds, which are only 100-microns wide - about the size of a human hair, notes Popular Science. According to a 2015 study, however, the diamonds in Almahata Sitta are much, much larger and were likely not produced by shock waves. If confirmed, they say, it would be the first time anyone has recovered fragments from one of our solar system's so-called "lost" planets.

Such planetary embryos got ejected from the solar system and either became rogue planets or smashed together.

"This study provides convincing evidence that the ureilite parent body was one such large "lost" planet before it was destroyed by collisions".