The first ultraviolet observations offer a more complete view of the huge asteroid Psyche


World rich in metals

The massive asteroid 16 Psyche is the subject of a new study by SwRI scientist Tracy Becker, who observed the object at ultraviolet wavelengths. Credit: NASA / JPL-Caltech / ASU

The researcher made the first observations of asteroids at medium ultraviolet wavelengths.

A new study written by Southwest Research Institute planetary scientist Dr. Tracy Becker discusses several new visions of asteroid 16 Psyche, including early ultraviolet observations. The study, which was published today in The Planetary Science Journal and presented at the virtual meeting of the American Astronomical Society’s Division for Planetary Sciences, paints a clearer view of the asteroid than was previously available.

With a diameter of about 140 miles, Psyche is one of the most massive objects in the main belt of asteroids orbiting between Mars is Jupiter. Previous observations indicate that Psyche is a dense, largely metallic object thought to be the residual core of a planet that has failed to form.

“We have seen meteorites that are mostly metallic, but Psyche could be unique in that it could be an asteroid that is totally made of iron and nickel,” Becker said. “The Earth has a metallic core, a mantle and a crust. It is possible that while a Psyche protoplanet was forming, it was hit by another object in our solar system and lost its mantle and crust. “

Becker observed the asteroid at two specific points in its rotation to fully visualize both sides of Psyche and outline as much as possible from observing the surface at ultraviolet (UV) wavelengths.

“We were able to identify for the first time on any asteroid what we think are ultraviolet iron oxide absorption bands,” he said. “This is an indication that oxidation is taking place on the asteroid, which could be the result of the solar wind hitting the surface.”

Becker’s study comes as NASA it is preparing to launch the Psyche probe, which will travel to the asteroid as part of an effort to understand the origin of planetary nuclei. The mission is scheduled to launch in 2022. Metallic asteroids are relatively rare in the solar system and scientists believe Psyche may offer a unique opportunity to see inside a planet.

“What makes Psyche and the other asteroids so interesting is that they are considered the building blocks of the solar system,” Becker said. “Understanding what a planet really makes up and potentially seeing the inside of a planet is fascinating. Once we get to Psyche, we will really understand if this is so, even if it will not go as we expect. Whenever there is a surprise, it is always exciting. “

Becker also noted that the asteroid’s surface may be mainly iron, but noted that the presence of even a small amount of iron could dominate UV observations. However, when observing Psyche, the asteroid appeared increasingly reflective at deeper UV wavelengths.

“This is something we need to study further,” he said. “This could be indicative that it has been exhibited in space for so long. This type of UV lightening is often attributed to space weather. “

Reference: “HST UV Observations of Asteroid (16) Psyche” by Tracy M. Becker, Nathaniel Cunningham, Philippa Molyneux, Lorenz Roth, Lori M. Feaga, Kurt D. Retherford, Zoe A. Landsman, Emma Peavler, Linda T. Elkins -Tanton and Jan-Erik Walhund, October 26, 2020, The Planetary Science Journal.
DOI: 10.3847 / PSJ / abb67e

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