Iron is essential in many ways. Rocky planets, plants, and animals all need iron to sustain themselves. Iron forms the core of crusty planets like Earth.
The symbol for the planet Mars has represented iron since Roman times. The same logo has been used for men since the Renaissance.
By contrast, the planet Venus, the ductile element copper, and women all share the same symbol.
The Sun and other stars store iron as a byproduct of the fusion that keeps them lit. Iron is the heaviest element made by stars. The employment of iron, especially as the main ingredient for steel, was essential to industrialization – man’s terminal mistake in generating a self-extinction event.
Plants use iron in chlorophyll, the pigment for photosynthesis. Vertebrates employ iron for hemoglobin molecules that ferry oxygen in blood.
Oatmeal, legumes, and spinach are high in iron.