SCIENTISTS in Scotland have used lasers to give an insight into the metallic core at the centre of our planet – and their findings could help us understand how Earth was formed from elements in space around 10 billion years ago.

They might also shed light on the fundamental physical nature of one of the most abundant elements in the atmosphere, nitrogen.

An international team of researchers at the University of Edinburgh, working with others in China and the US, carried out a series of sophisticated experiments to replicate conditions at the Earth’s core.

Using high energy laser beams, along with optical sensors, the were able to observe how samples of nitrogen behaved at more than 1 million times normal atmospheric pressure and at temperatures higher than 3000C.

The team’s observations confirmed that under these conditions nitrogen exists as a liquid metal.

Nitrogen – which makes up almost four-fifths of the Earth’s atmosphere – was discovered by Edinburgh physician, chemist and botanist Daniel Rutherford in 1772 and the findings give scientists a valuable insight into how it behaves in extreme conditions.

They could also help in giving an understanding of how the planets were formed.

They could help to explain why Earth is the only planet known to have an abundance of nitrogen in its atmosphere – where it exists as a gas. The findings might also shed light on how the planet’s atmosphere evolved and how it could develop in future.

Their study was published in the journal Nature Communications.

Dr Stewart McWilliams, of Edinburgh’s School of Physics and Astronomy, who took part in the study, said: “Earth’s atmosphere is the only one of all the planets where nitrogen is the main ingredient – greater even than oxygen.

“Our study shows this nitrogen could have emerged from deep inside the planet.”