Hard to spot water Chemical reactions producing water are common in space. The existence of huge amounts of water in many different regions was established four years ago. Other researchers in Spain have been studying regions of space where low-mass stars like our Sun are born. These regions are called 'quiescent' or 'cold' clouds, because they don't form massive stars and hence lack strong internal heat sources. They are at a mean temperature of minus 441 degrees F, just 10 degrees above absolute zero.
Astronomers estimate that there are millions of cold clouds in the Milky Way.
But researchers say the frigid temperatures make it difficult to detect water vapor, which does not emit radiation detectable by current telescopes. On the other hand, water in liquid form does not exist in space because the temperature and pressure conditions are not suitable. Consequently, only ices had been detected so far in cold clouds. But astronomers knew that water vapor should also be there, even if in small amounts. It was impossible to estimate the global amount of water in cold clouds, and its relative abundance as compared with other molecules, unless water vapor could be found.