Astronomers Release New, High-Detail Map of Asteroid 16 Psyche
NASA is preparing to launch a historic mission to study the asteroid 16 Psyche, but before the probe gets there, scientists have learned some important things about the mysterious object. The new study from MIT used data from the Atacama Large Millimeter/submillimeter Array (ALMA) to create the most accurate map of Psyche’s surface yet. Overall, they found the asteroid’s surface to be extremely varied, which will no doubt make for a fascinating up-close examination.
Just a few years ago, visiting any asteroid would have been unprecedented — but been there, done that, and got the samples to prove it. Still, visiting Psyche is important because it’s not just any asteroid. It’s the largest known M-type asteroid, which means it’s rich in metals. Astronomers believe this object, which sits in the Great Asteroid Belt between Mars and Jupiter, is actually the exposed metallic core of a planet from the early solar system. Studying it could help us understand planetary formation in entirely new ways.
Psyche is shaped like a lumpy potato, and it’s large for an asteroid with a mean diameter of 137 miles (222 kilometers). However, that’s too small for high-resolution observations with even the best optical telescopes of today. The ALMA data used in this analysis was gathered in 2019 using all 66 of the instrument’s radio antennas. Researchers synthesized those signals into a single signal, resulting in a virtual telescope about 10 miles across. With a resolution of 20 miles per pixel, it was possible to run computer simulations to generate the best map ever of Psyche’s likely composition. This same data was used to produce a high-resolution 3D shape model of Psyche in 2021.
The team compared the simulations to thermal emissions on Psyche to validate the model used in the study. You can see the results of the analysis above. The left figure shows the surface properties from sandy (purple) to rocky (yellow). The right figure shows metal content from low (purple) to high (yellow). The map hints at the asteroid’s history. Areas with higher rocky content could be the remains of an ancient mantle that was stripped away from collisions, and the highly metallic areas could be where early eruptions of metallic lava occurred.
This data on Psyche 16’s patchwork surface could help NASA prepare for the Psyche mission, which is set to launch in September aboard a SpaceX Falcon Heavy. It will take about three and a half years to reach the asteroid, at which time it will spend two years conducting observations.