Water molecules have been discovered on the surface of an asteroid in space, the first of its kind.
The water being detected may reveal new clues about how it is distributed in our solar system, scientists say.
Researchers studied four silicate-rich asteroids using data gathered by a telescope-outfitted plane operated by NASA and the German Aerospace Center.
Observations by the now-retired telescope, the Stratospheric Observatory for Infrared Astronomy (SOFIA), showed two of the asteroids, Iris and Massalia, exhibited a wavelength of light indicating water molecules were present on the surface, a study reports.
The findings were published in The Planetary Science Journal on February 12.
“Asteroids are leftovers from the planetary formation process, so their compositions vary depending on where they formed in the solar nebula,” study lead author Anicia Arredondo, of the Southwest Research Institute in San Antonio said.
“Of particular interest is the distribution of water on asteroids, because that can shed light on how water was delivered to Earth.”
Water molecules have been detected before in asteroid samples which have returned to Earth, but it’s the first time they’ve been discovered in space.
SOFIA found similar traces of water on the surface of the moon previously, in one of the largest craters found in the southern hemisphere.
Arredondo said: “We detected a feature that is unambiguously attributed to molecular water on the asteroids Iris and Massalia.
“We based our research on the success of the team that found molecular water on the sunlit surface of the moon. We thought we could use SOFIA to find this spectral signature on other bodies.”
The asteroids Iris and Massalia measure 199 kilometers and 135 km in diameter. They have similar orbits and travel an average distance of 2.39 astronomical units (AU), or sun-Earth distances, from the sun.
The findings suggest some silicate asteroids conserve some of their water and more may be found in the inner solar system. Asteroids are believed to be the primary source of Earth’s water after the Big Bang.
Scientists studying these events can help understand the distribution of water throughout space and help assess where to search for potential forms of life in our solar system.