Researchers at the Laboratory for Astrophysics of the Leiden Observatory have succeeded in producing water under conditions similar to those found in space.
Frozen oxygen was bombarded with hydrogen atoms in a special piece of apparatus. This resulted in the formation of water, but also of a number of other molecules which have since been observed with the Spitzer space telescope. For nearly five years the research team of Professor Harold Linnartz of the Leiden Laboratory and Dr Herma Cuppen (Radboud University Nijmegen) have worked on this result: a complete chemical recipe for the formation of water in space at temperatures of 260 degrees Celsius below zero.
At home you just turn on the tap, and water comes out. However, that water was not formed on earth. Our planet was much too hot for water formation when it was itself formed from the disc of dust, ice and gas that orbited around our sun 4.5 billion years ago. It was only after the earth had sufficiently cooled down that water became a possibility. This water was continually delivered in the course of a cosmic bombarding of ice remnants from this so-called protoplanetary disc.
The question is: how could water be formed there? The answer to this question is surprising. In one of the coldest and most empty spots in the Netherlands, Sergio Ioppolo (now Caltech and Radboud University Nijmegen) and Thanja Lamberts have bombarded frozen oxygen (O, O2 and O3) with hydrogen atoms. This imitates what happens in space, where at –260 degrees oxygen freezes on minuscule particles, and is then exposed to interactions with free hydrogen atoms. At typical interstellar temperatures, this apparently leads to the formation of both hydrogen peroxide (bleach) and water. In addition, a number of other molecules, including instable molecules, were found which turn out to be part of the cosmic recipe for water. 'And indeed,’ confirms Cuppen, ‘we have now observed these same molecules in space with the Spitzer space telescope.’
Image : Interstellar ice on a micrometre-size particle about to be hit by a hydrogen atom
Linnartz: 'We now have a consistent image of how water is formed in space, namely through so-called hydrogenation reactions of ice on small particles. 'This process takes place everywhere in our galaxy, as well as outside it, in other galaxies.’ So water is everywhere: this is an important conclusion. Limmartz continues: 'Recent research in Leiden has shown that other, more complex molecules can also be formed in interstellar ice. If you're looking for life elsewhere, then the building blocks of life must be readily available in situ and we are gaining increasing understanding of the chemistry required to make this possible. We are on the right track!’
The next step is to use this knowledge to explain the relationship between normal (H2O) and heavy (HDO and D20) water on earth and the processes as they take place in space. We need this information to understand where the water on earth comes from precisely and how high the odds are that there might be water on other planets, possibly around other stars.
Source : http://www.research.leiden.edu/news/making-water-at-260-degrees-below-zero.html