Rare Diamonds From A Long-Lost Planet Found In The Almahata Sitta Meteorites

These diamonds tell the tale of how our solar system was born, revealing there once was an additional planet that didn't make the cut.

View of the planet Earth from space during a meteorite impact.
sdecoret / Shutterstock

These diamonds tell the tale of how our solar system was born, revealing there once was an additional planet that didn't make the cut.

A decade after asteroid 2008 TC3 exploded over the Nubian Desert in northern Sudan, leaving behind a collection of small meteorites that would later be known as Almahata Sitta, researchers are still uncovering puzzling new details about this remarkable space rock.

According to NASA, this asteroid-turned-meteor was the first one to ever be detected in space before penetrating our planet’s atmosphere. But it turns out the asteroid is significant in more ways than one.

Although the asteroid’s composition didn’t remain a mystery for too long — the recovered 50 meteorites were quickly studied and identified as rare ureilites specked with tiny diamonds — little was known about where it had come from.

Now, for the first time in 10 years, a new study by scientists at the École Polytechnique Fédérale de Lausanne (EPFL) in Switzerland finally sheds some light into the asteroid’s planetary origin.

The paper, published in the journal Nature Communications, reveals that asteroid 2008 TC3 may have come from an ancient planet, formed early on during the birth of the solar system, reports the Washington Post.

The Swiss institute called it a planetary “embryo” — a proto-planet that was created in the early chaotic days when the solar system was just starting out, and that got torn apart by cosmic collisions some 4.5 billion years ago.

“There are many meteorites coming from Mars or the moon. However, this specific proto-planet has been destroyed in the early solar system and that is unique so far,” said lead researcher Dr. Farhang Nabiei of EPFL’s Earth and Planetary Science Laboratory.

His team reached this conclusion by examining the tiny diamonds found in the Almahata Sitta meteorites to determined their composition.

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.

“The analysis of the data showed that the diamonds had chromite, phosphate, and iron-nickel sulfides embedded in them – what scientists refer to as ‘inclusions’,” EPFL explained in a news release.

These are the same elements that diamonds found on Earth are typically made of. The novelty, however, is that they’ve never been documented “in an extraterrestrial body” before, shows the Swiss institute.

Since the tiny diamonds found in the Almahata Sitta meteorites have a similar composition to the ones here on Earth, the logical explanation of how they came to be is that they were fashioned in the same — by “the ‘normal’ static pressure inside the parent body,” notes the EPFL.

Judging by the materials’ shape and content, the diamonds encrusted in Almahata Sitta meteorites were formed under extreme internal pressure, pressure higher than 20 giga-Pascals, explains the Swiss institute. That’s 197,385 times the pressure of Earth’s atmosphere at sea level, reports the Daily Mail.

This means that the parent body inside which they were formed (i.e. the ancient planet where 2008 TC3 came from) was bigger than Mercury and possibly even as large as Mars.

Therefore, the Almahata Sitta meteorites finally confirm the existence of large proto-planetary bodies, which had only been speculated until now.

“These samples are coming from an era that we don’t have any access to,” said lead researcher Dr. Farhang Nabiei of EPFL’s Earth and Planetary Science Laboratory.

Although small in size — the largest ones measuring less than four inches, shows The Meteoritical Society — the Almahata Sitta meteorites help unravel the mysteries of our solar system’s early days.