Large craters offer clues to the origin of asteroid 16 Psyche

Researchers simulate impact scenarios to help NASA's Psyche mission unravel the asteroid's mysterious makeup.

Mar. 16, 2026 at 8:19pm

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Even 200 years after asteroid 16 Psyche was discovered, astronomers continue to puzzle over its formation. Psyche is the 10th-most massive asteroid in the main belt between Mars and Jupiter, and the largest known metallic asteroid, at 140 miles in diameter. NASA's Psyche mission will arrive in 2029 to determine its origin. Researchers at the University of Arizona's Lunar and Planetary Laboratory ran simulations to predict how a large crater near Psyche's north pole could have formed under competing ideas about Psyche's makeup, which may help settle the mystery of its origin.

Why it matters

Psyche may be a leftover building block of an early planet, shredded by violent collisions, or a planetary fragment that once separated into layers before losing its rocky outer mantle. Understanding Psyche's origin could provide insights into the early formation of planets in our solar system.

The details

The researchers used Smoothed Particle Hydrodynamics code to simulate the formation of Psyche's North Pole impact basin via an impactor striking the surface at a 45-degree angle. They tested two main interior structure models for Psyche: a layered structure with a metallic core and a thin, rocky mantle, and a uniform mixture of metal and silicate. The simulations showed that porosity, or the amount of empty space inside the asteroid, plays a significant role in how these craters form. Comparing the simulated craters with what the Psyche spacecraft observes will help scientists investigate whether Psyche's interior is separated into layers or a mixed-up jumble of materials.

  • Psyche was discovered over 200 years ago.
  • NASA's Psyche mission will arrive at the asteroid in 2029.

The players

Namya Baijal

A doctoral candidate at the University of Arizona's Lunar and Planetary Laboratory and first author of the study.

Erik Asphaug

A professor at the University of Arizona's Lunar and Planetary Laboratory and co-author of the study.

Adeene Denton

A postdoctoral researcher and co-author of the study.

Lindy Elkins-Tanton

The principal investigator of the Psyche mission at the University of California, Berkeley.

NASA's Jet Propulsion Laboratory

Responsible for the Psyche mission's overall management, system engineering, integration and test, and mission operations.

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What they’re saying

“Large impact basins or craters excavate deep into the asteroid, which gives clues about what its interior is made of. By simulating the formation of one of its largest craters, we were able to make testable predictions for Psyche's overall composition when the spacecraft arrives.”

— Namya Baijal, doctoral candidate at the LPL (arizona.edu)

“One of our main findings was that the porosity – the amount of empty space inside the asteroid – plays a significant role in how these craters form. Porosity is often ignored because it's difficult to include in models, but our simulations show it can strongly affect the impact process and shape of craters left behind.”

— Namya Baijal, doctoral candidate at the LPL (arizona.edu)

“We can't get to the cores of Earth or Mars or Venus, but maybe we can get to the core of an early asteroid.”

— Erik Asphaug, professor at the LPL (arizona.edu)

What’s next

When the Psyche spacecraft arrives at the asteroid in 2029, scientists will be able to compare the observed crater shapes and other features with the predictions from these simulations to help determine the asteroid's interior structure and composition.

The takeaway

By simulating the formation of Psyche's largest craters, researchers have made testable predictions that the Psyche spacecraft can use to unravel the mystery of this unique metallic asteroid and provide insights into the early formation of planets in our solar system.