Using data from a retired NASA mission, researchers identified unique signs of water molecules on two space rocks, unlocking new insight into how water may have arrived on Earth
In a cosmic first, scientists have discovered water on the surface of two asteroids. The findings, published Monday in The Planetary Science Journal, chart new territory in understanding how the life-sustaining molecule is distributed throughout the solar system—and hint at how it ended up on Earth.
Scientists at the Southwest Research Institute detected the water molecules using data collected by the now-defunct Stratospheric Observatory for Infrared Astronomy (SOFIA), a Boeing airplane modified to carry a telescope that made its final flight in 2022.
Previously, other researchers used an instrument on SOFIA to examine particular wavelengths of light, called spectral signatures, emitted by molecules on the moon. In 2020, they spotted a specific wavelength unique to water molecules, revealing enough water on the moon’s sunlit surface to fill a 12-ounce bottle.
Inspired by this research, “we thought we could use SOFIA to find this spectral signature on other bodies,” says Anicia Arredondo, lead author of the new study and an asteroid researcher at the Southwest Research Institute, in a statement.
The scientists studied SOFIA’s observations of four asteroids rich in silicate, or minerals containing silicon and oxygen. Two of the asteroids, named Iris and Massalia, were found to emit the unique wavelength that “unambiguously” indicated the presence of water molecules, Arredondo says in the statement.
Iris and Massalia, which measure 124 miles and 84 miles in diameter, respectively, formed relatively close to the sun. According to the study, their water could be stored in multiple ways: The molecules could be trapped in beads of silicate glass or stuck to the silicates’ surface. Or, in a manner similar to the moon’s sunlit surface, where the molecular water was found within lunar soil, the asteroids’ water may be bound to minerals.
Though scientists have discovered water on asteroid samples brought to Earth through return missions, water molecules had never before been identified on asteroids still floating in space, writes Space.com’s Samantha…
