Nanopaleomagnetism: How to extract and understand ancient extraterrestrial magnetic signals from meteorites using synchrotron X-rays

Magnetic signals recorded by meteorites provide invaluable information about the formation and evolution of our solar system. Before interpreting these signals, it is essential to understand how these signals are being recorded, and whether they are likely to be stable for billions of years. Over the last five years significant progress has been made in understanding the magnetic information recorded by iron-bearing meteorites. The bulk of meteoritic metal is kamacite (Fe0. 95Ni0. 05) which forms large mm-scale lamellae in the Widmanstätten pattern, a characteristic feature of slow-cooled iron meteorites. These kamacite lamellae are magnetically soft; they are multidomain and any magnetic information recorded is easily overwritten. Between the large-scale kamacite lamellae however, a range of microstructures form, including the cloudy zone. The cloudy zone consists of nanoscale islands of tetrataenite (Fe0. 5Ni0 …