A New Source of Water Discovered in Space

For the first time, scientists have detected water molecules on two silicate-rich asteroids, named Iris and Massalia, using data gathered by the FORCAST instrument on the Stratospheric Observatory for Infrared Astronomy (SOFIA), a telescope installed aboard an airplane and now retired from service.

This breakthrough represents a crucial step in the study of the primordial components of asteroids, remnants of planetary formation, and their potential contribution to bringing water to Earth.


The researchers analyzed four silicate-rich asteroids and observed in two of them, Iris and Massalia, a specific wavelength of light indicating the presence of water molecules on their surface. These asteroids, measuring approximately 124 miles and 84 miles in diameter respectively, share similar orbits around the Sun, at an average distance of 2.39 astronomical units (AU). The detection of water on their surface challenges the idea that asteroids near the Sun cannot retain water due to solar heat.

This discovery follows the finding of similar traces of water on the Moon's surface, revealing that water can be chemically bound to minerals or absorbed in silicates, both on the Moon and on asteroids. The implications of these observations are vast, suggesting that asteroids could have played a key role in bringing water to Earth, essential for life as we know it.

Analyzing the compositions of the asteroids provides valuable insight into the distribution of materials in the solar nebula and their evolution since the formation of the Solar System. By understanding better where and how water is retained in space, researchers can refine their searches for potential life, both within our solar system and beyond.

This study, published on February 12 in The Planetary Science Journal, opens new perspectives on the dynamics of water in the Solar System and its fundamental role in the history of our planet and potentially in that of other habitable worlds.