The asteroid Psyche will be the first metal-rich celestial body to be visited by a spacecraft. The NASA mission launches in 2022 and is expected to arrive at the asteroid in late 2026. A central question to be answered is whether Psyche is the exposed core of a protoplanet that was stripped of its rocky mantle. (NASA)
Deep inside the rocky planets of our solar system, as well as some solar system moons, is an iron-based core.
Some, such as Earth’s core, have an inner solid phase and outer molten phase, but the solar system cores studied so far are of significantly varied sizes and contain a pretty wide variety of elements alongside the iron. Mercury, for instance, is 85 percent core by volume and made up largely of iron, while our moon’s core is thought to be 20 percent of its volume and is mostly iron with some sulfur and nickel.
Iron cores like our own play a central role in creating a magnetic field around the planet, which in turn holds in the atmosphere and may well be essential to make a planet habitable. They are also key to understanding how planets form after a star is forged ...