Diamonds from ancient planet found in meteorite

Scientists from Switzerland, France and Germany studied the diamonds in the Almahata Sitta meteorite fragments that crashed into the Nubian Desert, Sudan, in October 2008. They concluded that they may have come from a primitive planet that existed at least 4.55 billion years ago.

The diamonds in the meteorite contain very small crystals that require high pressures to form, according to Philippe Gillet, a planetary scientist at the Federal Institute of Technology in Lausanne and co-author of the study. The team calculated the pressure required to be around 20 billion pascals (Pa). That would suggest the planet was at least as large as Mercury, or even Mars.

Scientists have long theorized that the early Solar System contained many more planets. One of the early planets, Theia, is thought to have collided with the young Earth, ejecting large amounts of material that would later form the Moon.

"We have in our hands the remains of the first generation of planets. This generation no longer exists today, either because it was destroyed or merged into a larger planet," said Gillet.

The method used in the new study is very robust and the conclusion seems plausible, according to Addi Bischoff, a meteorite expert at the University of Muenster. He said that further evidence of high pressure in the minerals surrounding the diamonds could be found.