The Erasure of Ancient Meteorite Data by Humans.

The use of neodymium magnets to validate meteorites is inadvertently erasing invaluable information locked inside ferromagnetic minerals, according to scientists from MIT and Paris Cité University. Many meteorites have a significant iron content, meaning important data on the way magnetic fields in space have altered these meteorites over billions of years is being lost. The study of these records is known as paleomagnetism, and scientists use them to understand the history of Earth's magnetic field and how it has evolved and changed over time. The research has shown that magnetic disruption is progressive, and follows a similar demagnetization curve, allowing scientists to find samples that retain fossilized magnetic fields, either from planetary processes, or the Solar System itself.