آهن به دانشمندان کمک کرد تا اکسیژن زمین را ردیابی کنند. اکنون داستان بزرگتری را بیان می کند

Iron helped scientists trace Earth's oxygen. Now it's telling a bigger story

For decades, scientists have studied iron preserved in ancient rocks to reconstruct how Earth's oceans and atmosphere became rich in oxygen. A new study suggests iron has recorded other major transformations too.