SoylentNews

takyon writes:

Space diamonds 'came from lost planet':

A diamond-bearing space rock that exploded in Earth's atmosphere in 2008 was part of a lost planet from the early Solar System, a study suggests.

The parent "proto-planet" existed billions of years ago before breaking up in a collision and would have been about as large as Mercury or Mars.

A team has published their results in the journal Nature Communications.

They argue that the pressures necessary to produce diamonds of this kind could only occur in [a] planet of this size.

A large planetary body inferred from diamond inclusions in a ureilite meteorite (open, DOI: 10.1038/s41467-018-03808-6) (DX)

Planetary formation models show that terrestrial planets are formed by the accretion of tens of Moon- to Mars-sized planetary embryos through energetic giant impacts. However, relics of these large proto-planets are yet to be found. Ureilites are one of the main families of achondritic meteorites and their parent body is believed to have been catastrophically disrupted by an impact during the first 10 million years of the solar system. Here we studied a section of the Almahata Sitta ureilite using transmission electron microscopy, where large diamonds were formed at high pressure inside the parent body. We discovered chromite, phosphate, and (Fe,Ni)-sulfide inclusions embedded in diamond. The composition and morphology of the inclusions can only be explained if the formation pressure was higher than 20 GPa. Such pressures suggest that the ureilite parent body was a Mercury- to Mars-sized planetary embryo.

Original Submission