There are a lot of upcoming space missions to be excited about; BepiColombo’s trip to Mercury, ExoMars, the Europa Clipper and New Horizons second flyby to name a few. One that has me really excited is Psyche.
Psyche is a NASA mission to explore the asteroid Psyche 16. This is an M-Class asteroid, which means that it is made dominantly of metals, mostly Nickle and Iron, compared most others types of asteroids which contain much more silicates (rock) within them. This unusual composition suggests that it is a relic left over from the formation of the planets.
Early in the life of the solar system, a protoplanetary disk of dust began to form clumps of rock as they collided, gradually these lumps of rocks grew into objects known as planetesimals.
When these planetesimals became large enough, the internal heat, generated by a mixture of gravitational energy, radioactive decay, and heat generated by collisions allowed those larger than about 30 km to internally separate out like oil and water; the denser materials sank to the bottom whilst the lighter material floated to the top. Iron, nickel, and a range of other metals sank to the bottom, it is this same process which formed the Earth’s core.
We have never sampled the Earth’s core, only being able to use seismic, magnetic, gravity and density data to infer information about it, as well as studying the limited number of meteorites which may be remnants of a core exposed by collisions with other planetesimals.
Psyche is the only known exposed planetesimal core in the solar system. This makes it a truly unique and exciting place to visit as it will enable us to look directly at and take measurements on the same kind of material which makes the core of the rocky planets. This will be the first time we have visited a metal body and is likely to look unlike any other body is so far seen in the solar system, possibly with impact craters showing metallic jagged edges.
The Psyche mission is scheduled to launch in 2022 and reach the asteroid in 2026, it will be exciting to see what new insights about the formation of the solar system and our own core.