Scientists at London University's Imperial College have gained a new insight into the earliest days of our solar system through a new analysis of some of the oldest, most primitive, metorites found on Earth.

The meteorites, all of which date back to the earliest days of the solar system, and predate our planet by a substantial period, are almost devoid of the so-called volatile elements, such as zinc, sodium, and lead, as is the upper mantle of Earth.

The nebula around the proto-sun would initially have been relatively rich in these elements, which leaves astronomers to puzzle over the question of when and where did these elements go?

The researchers propose that volatile depletion - the process by which these elements were knocked out of the matter that condensed to form the planets - must have been one of the first things to happen when our solar system was forming. Not only that, but they suggest that this process, whatever it was, could well be an inevitable part of planetary formation, and not just a local phenomenon.

Scientists have known for a long time that volatile depletion must have been an early process, but have not been able to say if it ocurredas the planets were forming, or some time later.

"Studying meteorites helps us to understand the initial evolution of the early Solar System, its environment, and what the material between stars is made of," Dr Phil Bland, from Imperial's Department of Earth Science and Engineering, who led the research, explained. "Our results answer one of a huge number of questions we have about the processes that converted a nebula of fine dust and gas into planets."

The researchers based their conclusions on an analysis of around half of the 45 primitive meteorites around the world. The work has been published in the journal Proceedings of the National Academy of Sciences, USA. ®