The discovery of water ice in the universe has experienced a boost thanks to recent discoveries that have helped us better understand the origin and distribution of water beyond Earth. These advances open up new avenues for understanding how water arrived on our planet and how this essential resource can be found distributed at different stages of star and planet formation.
For years, the interest of the scientific community has revolved around How water is formed and preserved in deep space, from vast clouds of gas and dust to comets, icy moons, and planets like our own. The recent observation of semi-heavy ice in a distant region is an essential piece of this complicated cosmic puzzle.
The revolutionary detection of semi-heavy water ice
Thanks to the most modern technology, in particular the use of James Webb Space Telescope (JWST), the presence of has been identified for the first time semi-heavy ice (HDO) around a young star with characteristics similar to our Sun. This discovery has occurred in the protostar L1527 IRS, located in the Taurus Molecular Cloud, about 460 light-years away, and represents the first direct observation of this molecule in the form of ice in an object of these characteristics.
The key component of this discovery is the accurate measurement of the amount of HDO in relation to H₂O in interstellar ice. The relevance of this information is that it allows us to deduce the extreme cold and chemical conditions that existed in that environment. Deuterium—the heavy hydrogen isotope present in HDO—usually incorporates into water molecules at extremely low temperatures, typical of the cold, dense clouds where star formation begins.
To date, previous measurements of the HDO/H₂O ratio at these sites have been limited and have almost always been made with water in a gaseous state, which does not guarantee that chemical changes have not occurred since its origin. direct observation of the ice It implies that the original composition has remained virtually intact from the beginning.
The importance of the HDO/H₂O ratio in space
The amount of Semi-heavy water detected in L1527 IRS It is very similar to that found in certain comets and in the protoplanetary disks of other stars. This suggests that much of the water now forming oceans or present in comets themselves comes from the same freezing processes in dark interstellar clouds, hundreds of thousands of years before the Sun and its planets formed.
For example, on Earth and in known comets, it is estimated that one in every several thousand water molecules is semi-heavy. The coincidence between these proportions and that of the analyzed protostar indicates that the Water that reaches planetary systems has not undergone major chemical alterations during their journey from deep space to places where life may appear.
Furthermore, when comparing the composition of the water in L1527 IRS with that of other protostars and regions of the universe, it is observed that the differences may be due to variations in temperature, radiation, or the density of the clouds where the different stars form. However, the results point to a great resistance of the interstellar ice to preserve its structure and composition over time and in different environments.
Implications for the origin of water in planetary systems
Measuring these proportions indicates that the water that forms the oceans and comets of our solar system It has traveled from the cold, dark clouds of outer space as ice, virtually unchanged, to end up in protoplanetary disks and ultimately in the planets themselves.
The fact that the proportions of HDO and H₂O remain stable even during the formation of stars and in the disks of matter surrounding them is essential to support the hypothesis that the Most planetary water is inherited directly from interstellar materialIn other words, the current water on Earth and elsewhere would have begun its journey long before the birth of our Sun.
The researchers emphasize that comparing these data with those from other star-forming regions and different types of stars will be necessary to confirm this general pattern. However, the finding provides strong support for the idea that the water cycle in the universe It is very efficient in preserving its content from its most primitive stages.
These advances mark a before and after for astrophysics, since they allow us to understand how the chemistry of interstellar ices influences the presence of water on planets, comets and moons billions of years after their formation.
With this new knowledge, the study of water ice in the universe takes a qualitative leap, offering certainties about its origin in the solar system and opening new lines of research on its role in the emergence of life beyond our planet.
