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For the first time, a NASA mission will embark on a far-flung journey to visit the metallic worlds of our solar system.
Scientists say getting close to the asteroid known as Psyche is the only way to determine whether it is the rare exposed core of an early planetary component.
This metal-rich asteroid is located in the main asteroid belt between the orbits of Mars and Jupiter. The spacecraft of the same name, Psyche, is scheduled to launch on Thursday.
Previous missions like OSIRIS-REX visited near-Earth asteroids that could potentially collide with Earth, but Psyche poses no threat to Earth. This giant space rock lies about 235 million to 309 million miles (378 million to 497 million kilometers) from the sun.
After launch, the mission will arrive in orbit around the asteroid in 2029 and spend about two years using an array of scientific instruments to study Psyche and determine its true nature.
NASA/JPL-California Institute of Technology/ASU
This diagram shows how scientists imagine the Psyche asteroid.
This asteroid was discovered on March 17, 1852 by Italian astronomer Annibale de Gaspari. Psyche, named after the Greek goddess of the soul, is the largest M-type, or metallic, asteroid in our star system.
“Psyche is the poster child for M-type asteroids,” Dr. Zoe Landsman, scientific advisor at the University of Central Florida’s Exolis Institute, said in an email. “Among a group of strange and mysterious asteroids, it is the largest, strangest, and most mysterious.”
The lumpy, potato-shaped space rock is 173 miles (about 280 kilometers) at its widest point and 144 miles (232 kilometers) long, according to NASA.
Psyche’s radar and telescope observations show that the asteroid likely contains iron, traces of nickel and other metals, all of which are abundant in the solar system, Landsmann said. However, the asteroid’s density suggests that it is not made of solid metal. Psyche also appears to contain some rock material, silicates, or substances found in glass and sand.
Researchers believe that Psyche began as the iron-rich core of a planetesimal, or perhaps an early planetary component similar to Earth and other terrestrial planets, from the beginning of the solar system. Over time, Psyche may have collided with other rocky objects and lost its outer shell and mantle until only a metallic core remained.
“But Psyche may be a more primitive object that never separated into a crust, mantle, and core,” Landsmann said. “That’s another big question that the mission can answer.”
New observations of Psyche were made in February 2022 using NASA’s now-retired Stratospheric Observatory for Infrared Astronomy, a Boeing 747SP aircraft equipped with a reflecting telescope. This observation confirms that Psyche is an iron-rich core.
NASA/JPL-California Institute of Technology/ASU
The Psyche spacecraft will spend about two years studying its namesake asteroid.
“Every time a new study about Psyche is published, more questions arise,” said Anicia Arredondo, lead author of the new paper on Psyche. Postdoctoral fellow at Southwest Research Institute in San Antonio.
“Our discovery suggests that this asteroid is very complex and may harbor many other surprises. The possibility of unexpected things happening remains unexplored. This is one of the most exciting parts of the mission to study the celestial body of Psyche, and we look forward to understanding Psyche’s origins in more detail.”
Dr. Arredondo presented the findings Monday at the 2023 Joint Annual Meeting of the Division of Planetary Sciences and the European Council on Planetary Sciences in San Antonio.
Scientists believe that studying Psyche could help answer important questions about planet formation. Earth, Mercury, and Mars have metallic cores, but they are too deep beneath the planets’ rocky shells to be seen or studied directly.
If the mission’s observations confirm that Psyche is indeed an exposed metallic core, astronomers could learn the truth about what lies at the center of the Earth. The spacecraft’s instruments will also look for signs of differentiation on the asteroid’s surface, as elements separate inside the planet and heavier materials (such as metals) sink to the center to form a core.
“Personally, I want to know what this is like!” Landsman said. “We have never seen the surface of a metal world up close. Asteroids do not have an atmosphere to protect them from space, and their surfaces are weathered by micrometeorite impacts and radiation. Does it look like this?”
A 2020 study hypothesized that a lump of iron as large as Psyche could be worth thousands of dollars, said Dr. Philip Metzger, a planetary physicist at the University of Central Florida in Florida. He said such a price tag could not really be placed on Psyche. Space Institute. Mining nearby asteroids could soon become a lucrative business, but Psyche is too far a target, he said.
“If we brought back as much metal as possible that could be present in Psyche, it would no longer be rare and the price would plummet,” Metzger said. “Secondly, the cost of transporting the metal back from Psyche in the far reaches of the universe is so high that it is not profitable at all.”