Asteroid 16 Psyche has been a subject of many studies over the years. The metallic asteroid was previously believed to be the exposed iron core of a planet that couldn’t form in its initial days. However, new research from the University of Arizona points out that the asteroid might not be as metallic as once believed, and suggests a different origin.
Astronomers have been studying the asteroid to understand an exposed planetary core up close. NASA is even planning to visit the asteroid in 2026 during its Psyche mission that will launch in 2022.
The asteroid isn’t metal-rich?
David Cantillo, lead author of the new paper published in The Planetary Science Journal argues that 16 Psyche is 82.5% metal, 7% low-iron pyroxene, and 10.5% carbonaceous chondrite. The paper also proposes that the asteroid’s bulk density is around 35%. It means there’s a difference from past analysis of the asteroid’s composition that led to a notion that 16 Psyche is 95% metal.
“That drop in metallic content and bulk density is interesting because it shows that 16 Psyche is more modified than previously thought,” Cantillo said.
Instead of being an exposed core of an early planet, it might be more of a rubble pile, similar to another widely studied Bennu asteroid. UArizona leads the science mission team for NASA’s OSIRIS-REx mission, which will bring Bennu asteroid’s surface sample back to Earth.
“Psyche as a rubble pile would be very unexpected, but our data continues to show low-density estimates despite its high metallic content,” Cantillo added.
Widely studied asteroid
Asteroid 16 Psyche, in Earthly terms, could be around the size of Massachusetts, and researchers suggest it could carry around 1% of asteroid belt material. The asteroid was first found by an Italian scientist in 1852 and is only the 16th asteroid to ever have found.
“Having a lower metallic content than once thought means that the asteroid could have been exposed to collisions with asteroids containing the more common carbonaceous chondrites, which deposited a surface layer that we are observing,” Cantillo said. This was also observed on asteroid Vesta by the NASA Dawn spacecraft.