Giant Metallic Asteroid Could Have Water on its Surface, Scientists Find
Scientists found possible evidence of water on the surface of a large metallic asteroid. The asteroid, named 16 Psyche, is one of the biggest in the Asteroid Belt, measuring 186 miles across and consisting of almost pure nickel-iron metal.
Researchers thought that the asteroid could be the remnant core of a planetary embryo that was destroyed by impacts billions of years ago.
Previous studies on Psyche showed no evidence of water on its surface. But new observations from NASA's Infrared Telescope Facility that the asteroid showed evidence for volatiles such as water or hydroxyl, which is a free radical consisting of one hydrogen atom bound to one oxygen atom. In Earth, hydroxyl is otherwise known as the "detergent of the atmosphere," as it is extremely reactive and removes many chemical compounds.
"We did not expect a metallic asteroid like Psyche to be covered by water and/or hydroxyl," Vishnu Reddy, an assistant professor at the University of Arizona's Lunar and Planetary Laboratory and author of the new study, said in a statement.
"Metal-rich asteroids like Psyche are thought to have formed under dry conditions without the presence of water or hydroxyl, so we were puzzled by our observations at first."
Results of the study were presented at the 48th meeting of the American Astronomical Society's Division for Planetary Sciences and 11th European Planetary Science Congress in Pasadena, California.
According to the researchers, the Asteroid Belt is located between the orbits of Mars and Jupiter, and these asteroids are fragments from the formation of the solar system. They typically fall into two categories: asteroids rich in silicates and those that are rich in carbon and volatiles. Psyche, which is a metallic asteroid, is extremely rare, and for this reason, scientists are studying the asteroid to know how planets are formed.
The researchers are still uncertain about the source of the water on Psyche's surface, but they propose two possibilities for its formation. First is that the water could have come from carbonaceous asteroids that impacted Psyche many years ago. Alternatively, the hydroxyl could be the product of solar wind interacting with silicate minerals on Psyche's surface.
NASA is currently reviewing a proposed $500 million mission to Psyche, which could enable scientists to distinguish between water and hydroxyl on the surface.