The core of the Earth is nearly 1,000 degrees hotter than previously thought, making it as fiery as the surface of the sun.
Following new experiments, scientists have established that the core temperature is 6,000 C, much higher than the previous estimate of 5,000.
Using X-rays to probe into the behaviour of iron crystals, putting samples of iron under extreme pressure, researchers were able to examine how iron crystals melt and form.
Hot stuff: The inner core of the Earth, previously thought to be 5,000 degrees Celsius is in fact 6,000
Earth's inner-core is a ball of solid iron, about the size of the moon, surrounded by a highly dynamic outer-core consisting mostly of a liquid iron-nickel alloy.
Experiments from the early Nineties, measuring the ‘melting curves’ of iron, suggested that the core had a temperature of 5,000.
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The new tests, using one of the world's most intense sources of X-rays located at the European Synchrotron Radiation Facility, the research team were able to re-create the same pressure at the core.
In order to do this the team used a device called a diamond anvil cell - essentially a tiny sample held between the points of two precision-machined synthetic diamonds.
Scorcher: The new estimate puts the core of the Earth at the same temperature as the surface of the sun
Then the scientists used X-ray beams to bounce X-rays off of the nuclei of the iron atoms, also known as ‘diffraction’, to see how the iron crystals behaved.
‘Other people made other measurements and calculations with computers and nothing was in agreement. It was not good for our field that we didn't agree with each other,’ Agnes Dewaele of the French research agency CEA and a co-author of the new research, told BBC News.
'We have to give answers to geophysicists, seismologists, geodynamicists - they need some data to feed their computer models,’ Dr Dewaele said.