Asteroid 16 Psyche is probably not a strong lump of metallic in any case, however simply one other heap of rubble
Asteroid 16 Psyche, often sensationally referred to as the $ 10,000 quadrillion asteroid due to its composition of precious metals, may not be quite what it seems. A new paper from the University of Arizona suggests that the asteroid may be more porous and less metallic than previous studies have shown. It certainly still has a mostly metallic structure, but its composition is more complex – and that’s good news. Given the impracticality of space mining (at least in the near future) 16 The real value of Psyche is scientific: planetary scientists believe it is likely to be the exposed core of a protoplanet from the early days of the solar system. Examining such an object up close would be hugely useful in understanding planet formation, and this paper is the latest attempt at understanding its structure.
The researchers based their work on previous observational data, which showed that the asteroid was primarily a mixture of three ingredients: metal, low-iron pyroxene, and carbonaceous chondrite. In the laboratory, they then tried to recreate the visible and near infrared spectra of the telescope observations with various mixtures of the three components. This enabled them to determine, with a greater degree of accuracy, the percentages of each ingredient that make up the surface area of 16 Psyche. The result was 82.5% metal (previously estimated at a staggering 94), 7% low iron pyroxene, and 10.5% carbonaceous chondrite. They were also able to determine that the density of the asteroid must be quite low with a porosity of about 35%.
Artist’s impression of 16 Psyche. Image source: NASA / JPL-Caltech / ASU
As lead author David Cantillo explains, “This decrease in metal content and bulk density is interesting as it shows that 16 psyche is more modified than previously thought … A lower metal content than previously thought means that the asteroid may have been exposed to collisions with asteroids that contain the more common carbonaceous chondrites that have deposited a surface layer that we observe. “
Low density is common with smaller asteroids. NASA’s OSIRIS-REx mission to the Bennu asteroid discovered that the building-sized object resembled a pile of rubble rather than a single boulder, with a porosity greater than 50%. But for larger objects like Psyche (the sixteenth largest asteroid in the solar system by diameter and ninth largest by mass – about the size of Massachusetts), such a low density came as a surprise. If 16 Psyche is really an old planetary core, it doesn’t look what we expect.
Rendering of the Psyche spacecraft, which is scheduled to arrive on the asteroid by 2026. NASA / JPL-Caltech / Arizona State Univ./Space Systems Loral / Peter Rubin
There’s only one way to find out what’s going on there, of course, and that is to visit it. NASA has been planning a robotic orbiter to visit 16 Psyche for years, and the launch date is getting closer. Originally planned to reach the asteroid in 2030, the schedule has been postponed to use a more direct orbit and the spacecraft will now launch in 2022 and arrive in 2026. What she’ll find when she gets there is unclear, but Cantillo’s research has given us a better understanding of what to expect and fueled the anticipation of more surprises.
Mikayla Mace Kelley, “Asteroid 16 Psyche Might Not Be What Scientists Expected.” University of Arizona.
David C. Cantillo et al., “Limiting the Regolith Composition of the Asteroid (16) Psyche Using Visible Near-Infrared Spectroscopy in the Laboratory.” The Planetary Science Journal