METEORITE hunters are unwittingly ruining their finds by swiping them with bar magnets. This common field test for identifying genuine meteorites could magnetise them and wipe them clean of subtle fields that tell us about the early Solar System.
Most terrestrial rocks aren’t magnetic because heavy metals like iron sank from the crust to the planet’s core while the Earth was still molten. In contrast, most meteorites are magnetised, and it was presumed this was because they had broken off iron-rich magnetic asteroids that formed in the primordial Solar System.
So when NASA’s NEAR space probe landed on the surface…
