The asteroid 16 Psyche (named as such because it was the 16th to be discovered) is believed to be the now-exposed core of a differentiated protoplanet that was smashed apart some billions of years ago. Its composition is generally estimated to be 90 percent metallic and 10 percent silicate rock. It’s thought to be much denser than a typical stony object of equivalent size, and it contains approximately 1 percent of the entire mass of the asteroid belt.
Assuming that the core is made of iron and nickel, the total value of the asteroid (if we ignore the impact on market prices) would be ~$10,000 quadrillion dollars. There’s a NASA mission to 16 Psyche expected to launch in 2022 and arrive in 2026, and the Hubble Space Telescope just spent some time surveying the core fragment. Psyche’s surface composition and what it’s made of have implications for the kinds of scientific tests and instruments that would be loaded on the probe we send to study the asteroid.
The researchers examined Psyche in the ultraviolet — it’s one of just a handful of asteroids to be examined this way — to see if telltale clues about how the light reflected off its surface could reveal details of the asteroid’s internal composition. The data they found generally supports a high iron composition for the object, but they noted that a relatively small amount of iron mixed into rocky materials like olivine can produce Psyche’s ultraviolet signature. This makes it “difficult to quantify the amount of iron that may present on the surface of Psyche.”