Water molecules on asteroids have been identified for the first time
16 February 2024

Scientists at the Southwest Research Institute have discovered water molecules on the surface of several asteroids for the first time. They were helped to make the discovery by data from the SOFIA Stratospheric Observatory of Infrared Astronomy, a mission of the American space agency NASA.
Scientists have studied four asteroids rich in silicates using the FORCAST instrument installed on board the stratospheric observatory. He helped analyze the spectral characteristics in the mid-infrared range, and the results indicated the presence of molecular water. The scientific portal writes about this Phys.org .
"Asteroids are remnants of the planet formation process, so their composition varies depending on where they formed in the solar nebula," says lead author Dr. Anicia Arredondo. "The distribution of water on asteroids is of particular interest, as it may shed light on how water got to Earth."
It is known that dry silicate asteroids formed near the Sun, and icy asteroids are dispersed in the outer part of the Solar System. The aim of the study was to understand how water, a key element for the formation of life, was distributed in the early Solar System.
"We have discovered a feature that is uniquely related to molecular water on the asteroids Iris and Massalia," Arredondo continues. - We based our research on data from a previous successful study by the team that discovered molecular water on the sunlit surface of the Moon. We hoped that with the help of the SOFIA observatory, we could find a similar spectral trace on other cosmic bodies."
Earlier, SOFIA instruments helped scientists detect water molecules in one of the largest craters in the southern hemisphere of the Moon. And a new study has shown that the ratio of the volume of water to minerals on asteroids generally corresponds to the ratio of the amount of water in the regolith on the illuminated side of the Moon.
"By analogy with the Moon on asteroids, water can also be bound to minerals, as well as adsorbed by silicates and trapped or dissolved in sandy impact glass," says Arredondo. As for the two other asteroids studied under the names Parthenope and Melpomene, their spectrum turned out to be weak enough for analysis. The FORCAST instrument is not sensitive enough to reliably analyze the spectral features of these asteroids and identify the presence of water.
The full study is published in the journal The Planetary Science Journal.
Source: Science