This works by firing an intense X-ray beam at a sample, and watching how atoms of the different elements inside the sample absorb the X-rays — it's an active probe, monitoring its own experiments. The beamline has an array of germanium detectors that can take 1 million measurements per second, according to an ESRF news release. So scientists could take a small sample of iron, put it in the beamline, heat it to 10,000 degrees, and watch what happens. This would conceivably help scientists understand how iron behaves 1,500 miles beneath the surface of the Earth, and what are the melting points of other metals present in the mantle and core. This, in turn, could shed some light on things like Earth's dynamo, which creates its magnetic field.